Relive how the 90 minutes of action unfolded with Sports Mole's live text coverage below.
This is just the second all-English final in UEFA's secondary competition, after Tottenham Hotspur against Wolverhampton Wanderers in the 1972 UEFA Cup, and is considered a make-or-break match for both sides.
A fifth-placed league finish in Unai Emery's first campaign at the helm will only be considered a success if Arsenal come out on top in Azerbaijan this evening, while Chelsea boss Maurizio Sarri has been under pressure all season long and could do with winning some silverware in what could be his final match in charge.
All things considered we could be in for a pretty explosive night! Let us get started by checking out some confirmed team news from Baku.
STARTING XI: Kepa; Azpilicueta, Christensen, Luiz, Emerson; Kante, Jorginho, Kovacic; Pedro, Giroud, Hazard
SUBS: Caballero, Cumming, Alonso, Barkley, Higuain, Zappacosta, Willian, Cahill, Ampadu, Gallagher, McEachran
Sarri described the Frenchman as "50-50" on the eve of the match but, having trained alone for just 20 minutes or so yesterday, it seemed certain he would miss out today. His inclusion is bad news for Ross Barkley, with Mateo Kovacic preferred to the left of Jorginho.
The other big call is on the right of the front three as Pedro is preferred to Willian, having performed well in the semi-final clash with Frankfurt. There is no surprise to see Eden Hazard complete the attack - this could be his last game for the club he has represented so well.
There were decisions to be made in midfield and attack, but the back four has effectively picked itself. Cesar Azpilicueta and David Luiz are regulars, while Emerson Palmieri recently usurped Marcos Alonso and Andreas Christensen profits from Antonio Rudiger's long-term layoff. Kepa Arrizabalaga continues in goal, meanwhile.
STARTING XI: Cech; Sokratis, Koscielny, Monreal; Maitland-Niles, Torreira, Xhaka, Kolasinac; Ozil; Lacazette, Aubameyang
SUBS: Leno, Lichtsteiner, Mustafi, Jenkinson, Elneny, Guendouzi, Willock, Saka, Amaechi, Iwobi, Nketiah, Welbeck
This will be Cech's final match in professional football before turning to coaching and, ironically, it looks as though he will begin his post-playing career with today's opponents. Some called for the veteran to be dropped today, but Emery has let his heart rule his head, it seems.
Ainsley Maitland-Niles and Sead Kolasinac continue to operate at wing-back and it is Lucas Torreira and Granit Xhaka who get the nod in holding midfield - again, as expected - with Matteo Guendouzi on the bench.
They have worked well in tandem in the latter stages of the Europa League, too, and they are responsible for each of their side's last eight goals - four apiece.
Their inclusion from the start today was a must, and fielding Mesut Ozil just off them was pretty much the only option for Emery given the injury absence of Aaron Ramsey and the loss of Henrikh Mkhitaryan because of political reasons.
The Blues are the first team to play a major European final without a player from their home nation in their starting XI since Inter Milan vs. Bayern Munich in the 2010 Champions League final.
UEFA were criticised for only awarding the two sides 12,000 tickets, but half of those have been sent back and serious questions have been asked of just why the game was staged here.
Anyway, the show must go on, as they say, and those in attendance should be treated to a good contest.
That is if reports from Italy over the last few days are to be believed, suggesting that an agreement is already in place between the Italian champions and the unpopular Chelsea chief. Sarri has denied that is the case, but I guess we will find out just how true the rumours are in the next few days.
This debut campaign in English football can be considered pretty mixed up to this point. Victory tonight, though, and there can surely be few complaints. Then again, this is football we are talking about...
In fact, there have been plenty of similarities between that season in 2013 and this one. Caretaker boss Rafael Benitez got the Blues over the line in UEFA's secondary competition but he was on his way out just a few days later due to fan unrest.
The most recent example came last year when Antonio Conte was sacked after guiding the Blues to FA Cup success, 12 months on from lifting the Premier League in impressive style. Sarri, then, cannot say that he had not been warned if he has to fall on his sword.
Or, alternatively, he cannot be blamed for jumping ship to Juventus if they are prepared to hand over the £5m compensation required to lure him away from Stamford Bridge!
This is not exactly new territory to Chelsea, then, having also triumphed in the biggest tournament of them all not so long ago when lifting the Champions League, whereas Arsenal's most recent chance of claiming continental success came in the 2005 Champions League final when losing to Barcelona.
Sarri's men required penalties to get the job done against Frankfurt, though, having played out a couple of 1-1 draws in the two legs of the semi-finals. Kepa was the hero of the hour in that one as he saved a couple of pens in the shootout - not the first time he has been the centre of attention this season, of course!
Incidentally, the two previous Italians to manage an English club in a major European final have managed Chelsea to victory - Gianluca Vialli in the 1998 Cup Winners' Cup final and Roberto Di Matteo in the 2012 Champions League final. The less said about the latter the better.
This will become the first fixture to be played in the FA Cup final, EFL Cup final and a major European final.
Tonight's clash will also mark the third time that two teams from the same nation have faced off in the Europa League final, after Porto vs. Braga in 2011 and Atletico Madrid vs. Athletic Bilbao in 2012.
This is the 198th meeting between the sides in all competitions but only the third in Europe - they also met in the 2003-04 Champions League quarter-finals, with the Blues progressing 3-2 on aggregate.
Emery also fielded Aubameyang and Lacazette up top that day in this same formation, so it is no surprise to see him retain the dangerous duo tonight.
The reverse league fixture, incidentally, finished in a 3-2 victory for the Blues in the second week of the season. Far less can be read into that game as both teams were still trying to find their feet under new managers.
Emery's men were favourites to finish fourth with a month of the season to go, only to win one game out of six prior to their final day dead-rubber against Burnley to finish in fifth. That only increases the pressure on the Gunners to prevail tonight.
It is fair to say, then, that it all comes down to this one match for Emery. Like Sarri, he is under pressure to achieve success while instilling his own style of play on his group of players; unlike his opposite number, though, he is not having to fend off questions regarding his job status - he will surely be at the Emirates Stadium next season whatever happens today.
Having fallen well short in both domestic cup competitions this term - they were knocked out of the EFL Cup by Tottenham Hotspur in the quarter-finals and by Manchester United in the fourth round of the FA Cup - the Gunners have a shot at redemption tonight, albeit in front of a small band of their dedicated supporters.
The North London outfit, it should be pointed out, have lost four of those last five major finals - their only victory came in the 1994 Cup Winners' Cup against Parma. In fact, they have lost three in a row when including the 1995 Cup Winners' Cup, 2000 UEFA Cup and 2006 Champions League finals.
Emery's side have not exactly enjoyed all that much continental success down the years. On top of that, there is also the opportunity for the Spaniard to make some history today if he lifts the trophy for a fourth time, which would be the ultimate reward for taking the competition seriously.
Emery's men managed to recover at the Emirates Stadium on both occasions and, with home advantage in the first leg of the quarter-finals and semi-finals, they saw off Napoli and Valencia with a bit left in the tank.
That, in the most respectful way possible, is very unlike Arsenal!
Azerbaijan will be the 24th different country to host a major European final and the third consecutive year a country will host a major final for the first time - Wales for the 2016-17 Champions League final and Ukraine for the 2017-18 Champions League final.
Both Arsenal and Chelsea have won 11 Europa League games this season, meanwhile - only three teams have ever won more major European games in a single season (excluding qualifiers); Real Madrid in 2001-02 (12), Porto in 2010-11 (12) and Atletico Madrid in 2011-12 (13).
Maurizio Sarri: "I want to think only of the final. I have a contract then for two years. Now is not the moment [to discuss my future]. Our feeling is that we want to win.
"In this moment, I love them. I have 22 wonderful men and players. I am really very happy. I have to consider it for the future. I have to consider that I love English football and the Premier League."
Unai Emery: "Our possibility is to win a title and play in the Champions League next year. Now I can say the same as when we started.
"It's going to be difficult. We can be, first, happy for this challenge and with a very big responsibility to do all to achieve that."
Arsenal impressed in the latter stages of the knockout rounds by overcoming Napoli and Valencia with convincing displays as they went one better than last season when crashing out in the semis under Wenger.
Chelsea have proven pedigree in UEFA's secondary competition, having gone all the way in their only previous participation in 2013, though they have some injury problems to contend with.
Only two points and two places separated the sides at the end of the regular campaign so a tight match can be expected in Baku.
We are tipping this one to finish all square, and then it comes down to a battle of nerves from the penalty spot - something Sarri's men have more recent experience with, which could prove telling. 1-1. Chelsea to win on pens.
There is plenty on the line for both teams tonight in what is one of the strangest London derbies ever contested between these sides. It is a pretty flat atmosphere in Baku with the ground not completely sold out.
I think it is probably a case of the two sides weighing each other up in these early stages, even if they do know each other well from the Premier League.
Neither team has been able to find any rhythm to their game yet as Giroud gets his head on the end of a hopeful pass to help out his side defensively.
It wasn't, though, and Aubameyang was well positioned to meet the loose ball, only to fire off target from a good position.
Giroud is fouled by Sokratis and the Blues have a chance to send in a free kick from a wide position, 30 yards out.
A simple ball in behind catches the Blues out but Kolasinac takes too long and Azpilicueta blocks it behind.
It presumably went to a VAR check but it was over in seconds and no penalty is given. That is a controversial one, to say the least!
The cross comes into the box and Jorginho is waiting to help it behind for a corner, which Xhaka curls in for Luiz to head away - that was a good defensive clearance.
The two Chelsea players collide in the process and are both a little groggy but will be fine to continue.
The Greek defender could not adjust his feet in time, though, and the opportunity went begging.
Up the other end, Giroud is picked out in the box at the end of a swift counter but he miscontrols the ball.
The Blues have been second best in the opening half an hour but it remains all square and they will surely only improve.
From the same move, Xhaka seriously puts his boot through the ball from range and clips the crossbar with his belter. So nearly the opener for Arsenal!
The attempt is on target but Sokratis throws his body in the way to concede a corner - good defending.
One of these efforts from the Gunners will end up in the back of the net. Chelsea need to get out of first gear before they are punished.
The Blues are enjoying a good spell on the ball but some neat, one-touch play ends with the ball hitting Giroud and trickling behind for a goal kick.
Kolasinac curls the ball into the six-yard box and Kepa, for some reason, elects to slap it away rather than catching. The Chelsea keeper has been pretty poor today.
That says a lot about how this first half has panned out. There are around six minutes to go until half time in Baku.
Giroud took it on early to try to catch out the ex-Blues keeper, but he used all his years of experience to read the danger.
Arsenal have still edged the opening 45 minutes, I'd say, but the Blues have looked a lot better in the last 10 minutes.
A nervy Kepa Arrizabalaga raced off his line and appeared to clip his opponent's legs, but the referee Gianluca Rocchi did not feel that there was enough contact. Replays suggest he had a point.
Chelsea ended the first half on top, however, with Emerson Palmieri and Olivier Giroud both testing Cech - the latter nearly picking out the far corner from the edge of the box, only for Cech to produce a fine save down to his left.
CHELSEA SUBS: Caballero, Cumming, Alonso, Barkley, Higuain, Zappacosta, Willian, Cahill, Ampadu, Gallagher, McEachran
ARSENAL SUBS: Leno, Lichtsteiner, Mustafi, Jenkinson, Elneny, Guendouzi, Willock, Saka, Amaechi, Iwobi, Nketiah, Welbeck
Things can surely only get better in the second half. Remember, extra time and penalties await if required.
Hazard glides forward - the first time we have seen that today - and plays in Giroud. The striker's shot is deflected behind for a corner, though Chelsea ask why a free kick was not given for a shove on Hazard.
Emerson's cross was flat, but Giroud managed to stoop down in front of Koscielny and guide his header away from Cech into the bottom corner. A goal from nothing!
The striker scored 103 goals for Arsenal prior to joining Chelsea, so the Gunners fans in attendance here will be hurting even more. Can Emery's side respond?
He initially stays down and signals towards the bench but he is now back on his feet and able to continue.
Pedro is the first player to be cautioned for dissent.
Arsenal have it all to do now having failed to get going since the restart. Is that game over?
The way this one is shaping up, Chelsea are going to get chances to hit their opponents on the counter.
The Belgian forward sends the penalty pretty much down the middle, with Cech unable to get a foot to it.
Xhaka's free kick was only half cleared and Iwobi sent a sweetly-struck half volley flying past Kepa from outside the box.
Great link-up play and a great finish. That should do it for Chelsea!
Arsenal get the ball forward quickly but Aubameyang is forced wide by Luiz and cannot keep his shot on target. It has been a very open second half.
The Blues lead 4-1 with a little over 10 minutes to play in Baku. It is game over.
The German playmaker is replaced by Willock as the clock continues to tick down. Another goal for Arsenal in the next few minutes and maybe, just maybe, the comeback could be on.
There is a case to be made that the veteran goalkeeper has been the Gunners' best player on his final appearance before retirement.
Arsenal have almost given up and they are at risk of shipping a fifth and possibly a sixth before full time at this rate.
Aubameyang is first to the rebound but his shot is blocked on the line by Christensen. We have had five goals in the second half but there could easily have been double that amount!
Zappacosta comes on in his place as Sarri throws on an extra defender for the closing stages.
Willock wins the Gunners a late corner which comes to little.
The referee is not ready to blow his whistle just yet but there are only around 15 seconds to go in Baku...
Following a goalless first half in Baku, Giroud opened the scoring early in the second half, Pedro added a second and Hazard made it 3-0 in a calamitous 20-minute spell for the Gunners.
Iwobi pulled one back through the best goal of the game shortly after coming off the bench, only for Hazard to double his personal tally to kill off the tie in what is likely to be his final game for the club.
An on-the-whistle report can be found by clicking here, and be sure to stick around as we bring you reaction from both camps.
We will be back with live updates from the Champions League final between Liverpool and Tottenham Hotspur on Saturday. See you then!