Theo Walcott netted a quick-fire double before Rob Holding added a third all in the opening 25 minutes, but Mirko Ivanic reduced the deficit before the break.
However, Olivier Giroud's penalty reopened Arsenal's sizeable lead and although Mikhail Gordeichuk added a second for BATE, the home side were unable to get closer to the Gunners before the full-time whistle.
Find out how all of the action unfolded at the Borisov Arena courtesy of Sports Mole's minute-by-minute updates below.
5.00pmHello and welcome to Sports Mole's live coverage of this evening's Europa League clash between BATE Borisov and Arsenal. Gunners boss may be placing most of his focus on trying to achieve a top-four place in the Premier League table but don't be fooled - the Frenchman still wants to go far in this competition. Let's find out who he has selected for tonight's game in Belarus.
5.06pmIn his pre-match press conference, Wenger indicated that he would field "no more than two" of his younger players and the Gunners boss has lived up to his word by including just Reiss Nelson and Joe Willock in his starting lineup. The remainder of the more youthful contingent have to begin the game on the bench.
5.08pmWenger also stated that Ainslye Maitland-Niles was best suited to playing in a defensive-midfield role, but for whatever reason, the England Under-20 hero has been positioned at left wing-back. He is capable of playing in that role - and on the right-hand side, too - but it is a surprise to see him used from the start against a team such as BATE.
5.10pmWe will look at the remainder of the side starting with the attack, where both Theo Walcott and Olivier Giroud are given rare starts - based on this season's matches anyway. They are joined by Jack Wilshere, who will be hoping to get another 90 minutes under his belt as he continues his recovering from a fractured ankle.
5.12pmWe have already mentioned the inclusion's of Nelson, Willock and Maitland-Niles and they will be joined in the midfield by Mohamed Elneny, who remains in a bit-part role at the Emirates Stadium. You would expect the Egyptian enforcer to operate just in front of the back three this evening, with Willock perhaps having more licence to join Wilshere further forward.
5.14pmThe backline is full of experience with Per Mertesacker and Shkodran Mustafi both featuring alongside Rob Holding. Holding is obviously the more youthful of the trip but after gaining regular match action with the North Londoners since his arrival from Bolton Wanderers, it is no longer considered a risk to select him.
5.16pmDavid Ospina is entrusted with the role between the sticks, with Petr Cech being left in England. Matt Macey is Arsenal's third choice this season - with Emiliano Martinez out on loan - so he is given a rare appearance on the bench.
5.19pmAll in all, Wenger has made a total of nine changes to the team which defeated West Bromwich Albion on Monday night. There are even more among the replacements, with each of the six outfield players possessing little to no first-team experience. We are sure that will change over the course of the 90 minutes.
5.22pmAs for BATE Borisov, their team is largely made up of players who represent the Belarusian national team squad. Serbian defender Nemanja Milunovic is the one player who goes against the norm, while Finnish representative Jasse Tuominen features among the substitutes.
5.24pmBATE earned their draw with Red Star Belgrade courtesy of a goal from Mikalay Signevich, but manager Alyaksandr Yermakovich has decided that his reward for getting a point on the board for his team in a spot among six others on the bench.
5.26pmDespite both clubs being regulars on the European scene, this is the first time that they had met in a competitive match. This evening also marks the first time that Arsenal have faced a Belarusian team.
5.28pmRemaining on a Belarusian theme, BATE are unbeaten in their last seven home games - a run Arsenal will hope to dent tonight. The last time that they suffered a home defeat in Europe was back in 2015, when Barcelona ran out 2-0 winners at the Borisov Stadium.
5.31pmBATE have won the Belarus Premier League title in each of the last 11 years but it may be a different story this year.
With seven games to go, the defending champions sit two points off the pace in third, with Shakhtyor Soligorsk currently leading the way.
5.34pmLet's get back to Arsenal, and take a more in-depth look at some of the younger players which have been selected in tonight's 18-man squad.
Reiss Nelson probably needs less introduction after impressing during pre-season and featuring off the bench against Chelsea in the Community Shield and FC Koln two weeks ago. He stepped up his developed with an 84-minute showing against Doncaster Rovers in the EFL Cup and there are all the signs that Wenger is prepared to place a lot of faith in his ability.
5.36pmWillock and Jay Dasilva were both introduced during that same game against the League One side, but Gunners fans may know a little less about the others.
Vlad Dragomir has been described as a "number 10, Wilshere-like player" by Wenger, while you may be aware of Marcus McGuane after he was given the privilege of training with the first team ahead of the FA Cup final in May.
5.38pmHis appearance in the squad tonight may also be down to his current contract situation. He is at a stage where he needs to either commit to the Gunners or take advantage of the interest being shown in him elsewhere from the likes of Juventus and Manchester United. Make no mistake about it - he will be desperate to impress a lot of people should he take to the pitch later tonight.
5.41pmAt this stage of the season, Chuba Akpom is usually on loan at a Football League club but on this occasion, he has been kept in North London. The 21-year-old remains with just one start and nine substitute appearances to his name, with five separate loan spells being undertaken elsewhere. The forward failed to score in 10 outings for Brighton & Hove Albion during the second half of the last campaign.
5.43pmGoing back to Walcott and Giroud, they have played a total of just 143 minutes between them in the Premier League this season. It remains a frustrating time for the pair - who will now recognise their backseat role at the club - but there remains pressure on them to perform incase they need to fill in for Alexis Sanchez, Danny Welbeck and Alexandre Lacazette.
5.45pmAfter Arsenal's 4-0 thrashing off Liverpool in August, much was said about the steel and toughness of the Gunners but to their credit, their response has been exemplary. Four clean sheets have been kept in five games, including a shutout against Chelsea at Stamford Bridge. Changes have been made for tonight's game, but it is a record which Wenger will want to preserve.
5.47pmThe only goal conceded during that time came against FC Koln on matchday one but in all fairness, Arsenal simply deserved credit for winning that game given the crowd trouble beforehand. Kickoff was delayed by an hour - thus disrupting everyone's usual plans - but the Premier League put in an efficient performance to run out deserved winners.
5.50pmSead Kolasinac and Sanchez both netted during that game but neither are involved this evening. It highlights the theory that these games can be used to either bed in new talent or improve the sharpness of players who are coming back from injury or haven't been used. There are a number of players who find themselves in similar scenarios tonight.
5.53pmPREDICTION! Despite the mass alterations, we cannot back against Arsenal this evening. They don't always perform on their travels in Europe but this should be a refreshed team featuring players who want to send a message to their manager. It may be tight, but we are predicting a 2-1 win for the visitors.
5.55pmThe other game in this group sees FC Koln play host to Red Star Belgrade. Ideally, Arsenal will be looking for that match to finish as a draw. We will keep you updated with any goals.
5.57pmThe two teams have made their way out at the Borisov Stadium. Arsenal's supporters have travelled in their numbers.
A reminder of the main team news: Nelson and Willock start, as does Wilshere. Maitland-Niles is deployed at left wing-back. Giroud is in attack alongside Walcott.
2 minThe BATE supporters are making a right old racket. This is much more of a big occasion than it is to Arsenal.
Nothing doing so far. Just an offside for either side.
3 minSHOT! There is ambitious and then there is whatever this is. Ivanic tries a volley off balance from 35 yards out but he gets his effort all wrong.
5 minWe've just seen the first example of Nelson's blistering pace but if we were to use FIFA's ratings to judge his touch, it would be a 27. He overhits the ball and commits a foul.
7 minIt's been an extremely quiet start in Belarus. Arsenal are dominating possession while BATE have had one break forward but aside from that, neither team are offering much encouraging play.
8 minWOODWORK! Walcott strikes the post. A pinpoint pass from Wilshere finds the run of Walcott but despite getting ahead of the defender, the forward pokes the ball against the foot of the post.
9 minGOAL! BATE Borisov 0-1 Arsenal (Theo Walcott)
9 minA minute later, the same pair combine and it's 1-0 to the Arsenal. Wilshere surges into the penalty area and although Walcott heads straight at the goalkeeper after being found by his teammate, he volleys home the rebound. Perfect start for the English side.
12 minRight now, Arsenal are making easy work of BATE, who look several classes below. This should turn out to be a comfortable night's efforts, but Arsenal need a second to make that a reality.
14 minArsenal have reverted back to holding onto the ball but that's all they have to do right now. Make BATE do the work if they want to get back into the match. Ospina has barely had anything to do so far.
16 minWillock is trying to play an active role in both defensive and attacking areas but he remains on the periphery of the game so far. He's doing little wrong, but nothing that impressive at the same time.
17 minWilshere has the ball in the back of the net after converting a Walcott cross from cross range but one of the two was adjudged to have been offside. It certainly wasn't Wilshere, but Walcott looked level too. BATE have gotten lucky.
19 minSHOT! BATE finally have a small sustained spell of possession in the Arsenal half but with the Gunners making a wall of six on the edge of the area, Ivanic blazes miles over the crossbar from distance.
20 minSHOT! Another opportunity for Ivanic and this one was much better than the previous two. Arsenal only half-cleared a cross to the edge of the area but the Montenegrin's volley was dragged just wide of the post.
22 minGOAL! BATE Borisov 0-2 Arsenal (Theo Walcott)
22 minThat's probably game over already. Goalkeeper Scherbitskiy passes the ball straight to Walcott, who ignores the support from Giroud to slot the ball into the bottom corner from 10 yards out.
25 minGOAL! BATE Borisov 0-3 Arsenal (Rob Holding)
25 minBATE are astonishingly poor. After Maitland-Niles is denied by a clearance in the six-yard box, Walcott's set piece finds Mertesacker, who heads the ball into the path of Holding who converts from close range for his first Arsenal goal.
27 minGOAL! BATE Borisov 1-3 Arsenal (Mirko Ivanic)
27 minThe home side are back in it! This is a crazy game. Ryas's cross finds the head of Ivanic, who directs the ball into the top corner at the near post. Wenger will be raging.
30 minWe have gone three minutes since a goal. It's getting a little boring...
Arsenal failed to create anything from a free kick and have gone back to spraying the ball around in the defensive and middle third of the pitch.
32 minOspina to the rescue! A player is eventually adjudged to be offside but Ospina wasn't aware as he flung himself to his left to keep out a free kick from the touchline. All of a sudden, Arsenal look distinctly average.
33 minCHANCE! Where was this BATE Borisov in the opening 25 minutes? Ivanic is everywhere and his volley across goal is well claimed by Ospina.
35 minWe haven't seen much animation from Wenger. He looks happy to sit back and watch how his second-string perform without any further instruction. Maybe he is looking to see how his youngsters react to a bit of adversity.
38 minI'm as tired as some of the players must be. This has been a relentless game. Arsenal are still shading possession but they don't have that same sparkle in the final third. The flicks which were coming off, aren't now.
40 minBATE hold wins over the likes of Bayern Munich, Athletic Bilbao and Roma on this ground. Arsenal still have some way to go to put a dent in that record but it's so far so good, despite conceding soon after their third goal.
42 minWillock has just been caught by the flailing arm of Milunovic. It is straight in front of the referee but the official has decided to do nothing but halt play for some treatment!
43 minCHANCE! Walcott should have his hat-trick. The ball falls invitingly to him from around eight yards out and his volley is heading for the corner. However, Scherbitskiy makes a phenomenal save with his fingertips.
44 minWOODWORK! Now Holding strikes the post! Again, a corner from Walcott causes all kinds of confusion but despite the ball falling for the defender, he slices his effort against the woodwork.
6.49pmThe half-time whistle goes in Belarus and Arsenal deservedly lead by a 3-1 scoreline. Walcott has two and Holding has netted a third, but both players should have more to their tally. BATE have been poor at the back, but they look capable of getting another goal or two in this match. There's still all to play for.
6.54pmIn the other game in Group H, Red Star Belgrade have taken the lead in Germany against FC Koln. If the home side can equalise during the second half, that would represent perfection for Wenger.
6.57pmIn the Arsenal changing room right now, I'm sure that Wenger is demanding a fourth goal so that he can take the opportunity to introduce a few of the academy crop. Nelson and Willock are already picking up valuable experience, although neither have really set the world on fire on the right flank or in midfield.
7.01pmWe are all ready to go in the second half. There have been no changes from either side.
46 minBATE get us back underway for the second half.
49 minThis is the softest penalty you will ever see. Dragun has stepped on Mustafi's toe and pulled him back ever so slightly, but the referee has awarded the spot kick.
49 minGOAL! BATE Borisov 1-4 Arsenal (Olivier Giroud)
49 minGiroud takes responsibility for the penalty - rather than Walcott - and the Frenchman sends the goalkeeper the wrong way. Definitely game over now...
52 minIncidentally, that was Giroud's 100th goal in an Arsenal shirt. He has had to wait since the opening day of the season to finally get there.
54 minI have a feeling that the Europa League could benefit Arsenal. So many players are getting the opportunity to get some match practice under their belt and they are going to coast through to the knockout stages. Arsenal are still forcing the pace to a certain extent but they can afford to relax now.
55 minSUBSTITUTION! We finally get to see Signevich - who scored on matchday one. Rodionov is the man to make way.
57 minSAVE! The marking from this BATE free kick is terrible and Signevich should head in from close range. However, Ospina, fortunately, doesn't move and is able to get a hand in front of the ball.
59 minWithout showing any favouritism in the slightest, Arsenal have had some shocking decisions go against them tonight. Giroud has just been denied a clear free kick from 20 yards. That said, the awarding of a penalty was equally outrageous so the referee is just having a bad night.
62 minOn this occasion, the referee recognises the foul but decides to wave play on when Arsenal don't necessarily want it. It has been one of those nights for the main official.
63 minSHOT! Ryas opts to try his luck from around 30 yards out but the ball fizzes marginally wide of the far post. Ospina didn't move but he didn't really need to.
64 minBOOKING! Milunovic should have had a red in the first half, but he enters the book now for a foul on Walcott on the right-hand side of the penalty area.
66 minBATE are still giving this a go. Arsenal could easily be out of sight but the home side are ensuring that they cannot afford to completely switch off.
67 minGOAL! BATE Borisov 2-4 Arsenal (Mikhail Gordeichuk)
67 minThere you go. BATE are back in it. Some of Arsenal's defending has been abysmal and after Ospina makes a fine block to deny Ivanic, Gordeichuk is able to leather the ball into the roof of the net from close range.
70 minThere are still no signs of any of Arsenal's youngsters being thrown on. It is a consequence of the senior players not doing their job at the back.
71 minCHANCE! My word. It should be 4-3. Volodko should score from around 14 yards out after being teed up all on his own but somehow, he blazes the ball wide of the post!
73 minArsenal are showing very little regard to their defensive responsibilities. They break forward in numbers but Giroud ends up seeing his cross deflected over for a corner, which comes to nothing.
75 minCHANCE! Another opportunity for BATE but again, it is Ospina to the rescue. Stasevich is denied at the near post with Ospina claiming at the second time of asking.
77 minCHANCE! Back up the other end, Nelson breezes past a couple of players after cutting inside the pitch before teeing up Giroud, but the forward slashes at his first-team effort and it goes horribly wide.
79 minSUBSTITUTION! Finally, Wenger makes a change. Marcus McGuane is on for Nelson. I'm assuming that there will be a change in formation.
81 minSHOT! Arsenal are visibly tiring but they continue to create chances. On this occasion, Giroud tried to find the far top corner from 25 yards but his effort landed on top of the net.
83 minCHANCE! If Walcott looks up and finds Willock, it's 5-2. Instead, he shoots from a silly angle and the ball goes straight across goal.
85 minSUBSTITUTION! A final switch for BATE sees Baha replace Volodko.
87 minBOOKING! A silly foul from Ivanic on Giroud breaks up play and earns the attacker a yellow card.
89 minSUBSTITUTION! Off comes Willock, who is exhausted. Nketiah is on for his debut.
7.53pmThe full-time whistle goes in Belarus and Arsenal have comfortably held on for a 4-2 victory over BATE. At one stage in the second half, it appeared as though the home side were going to pull a further goal back but the Gunners saw off the pressure to claim a deserved win.
7.58pmIn the other game in this group, Red Star Belgrade held on to see off FC Koln. The Serbian outfit appear to be Arsenal's main challengers in Group H and remain two points adrift.
That will be all from Sports Mole for this game. If you want to read a match report on Arsenal's triumph, click here. Goodbye for now.