Arsene Wenger celebrates 20 years in charge of Arsenal this week, but the milestone could be tarnished if his team do not overcome London rivals Chelsea at the Emirates in the late kickoff on Saturday.
The Gunners are aiming to extend their unbeaten run to seven games in all competitions, while their fellow Premier League title contenders are winless in their past two matches in the top flight.
Three Premier League titles, six FA Cup trophies and consecutive Champions League qualifications are among Wenger's achievements during his 20-year spell in charge of Arsenal.
The Frenchman is currently the longest-serving manager still competing in the Premier League and it could be his final season at the club given that his contract runs out next summer.
The 66-year-old has admitted his fears about stepping down from a job that he has made his own, but there has not been any indication as yet that he will be offered a new contract.
It should be a celebratory occasion this weekend, but Chelsea have been known in the past to ruin Wenger's party. The Gunners boss recorded a 1-0 defeat to the Blues in his 500th match in charge in 2005.
Just two years ago, Chelsea were a dark cloud over Wenger's 1,000th game at the helm when they thrashed Arsenal 6-0, and the West London outfit will be hoping to cause an upset on another landmark week for the Frenchman.
Arguably, if Jose Mourinho were still in charge of Chelsea, the Blues may have had a much stronger desire to ruin Wenger's day given that the pair appear to have a tense relationship.
So much so that a new book has alleged that Mourinho once threatened to break Wenger's face, but the Arsenal boss refused to bite when the comments were brought up in his weekly press conference.
Mourinho will not be in the opposing dugout this weekend as he is now in charge of Manchester United, but the ever-enthusiastic Antonio Conte will be.
The last time that the Italian went up against Wenger was in 2002 when his Juventus team knocked the Gunners out of the Champions League in Turin.
The pressure is on Arsenal to have a successful season after they squandered an opportunity to win the title in the 2015-16 campaign - eventually dropping 10 points behind eventual champions Leicester City.
After their 4-3 defeat to Liverpool on the opening day of this season, Arsenal have gone on to secure one draw and three back-to-back wins in the top flight, putting them five points behind league leaders Manchester City.
Wenger's summer signings are also starting to come good, with Shkodran Mustafi settling into a defensive partnership with Laurent Koscielny, while Lucas Perez and Granit Xhaka have been among the goals of late.
Not only can Arsenal celebrate Wenger's milestone, they also have the chance to win four consecutive league games for the first time since their successful run in October 2015.
The team head into this fixture in decent form having suffered defeat in just one of their last 15 league matches.
Recent form: LDWWW
Recent form (all competitions): WWDWW
It is too early to say that Chelsea are under pressure, but if they record a third successive Premier League match without a win, questions may be raised.
Conte, who has not gone three league games without a win since March 2012, headed to Stamford Bridge in the summer with expectations on his shoulders following last season's disappointing campaign.
The former Italy coach started well by guiding the Blues to three consecutive victories against West Ham United, Watford and Burnley, but they hit a snag against Swansea City and Liverpool.
The following weekend, they were given a test by Liverpool, who dominated the first half and sealed a 2-1 victory as Conte's men failed to get a stronghold in the game.
Chelsea supporters would be forgiven for feeling nervous when Shinji Okazaki put Leicester 2-0 ahead in the first half of their EFL Cup third-round tie in midweek, but goals from Gary Cahill and Cesar Azpilicueta forced the match into extra time.
The Blues may not be able to rescue themselves if they slip behind against Arsenal at the Emirates this weekend, though, and from Conte's perspective, he will not want an unwelcome personal statistic of back-to-back league defeats for the first time since December 2009.
Defence has been an issue for Chelsea as they have only managed to record one shutout in their last 12 top-flight fixtures, and they have not been any stronger at the back on their travels given that they have conceded in all of their last six away league matches.
Recent form: WWWDL
Recent form (all competitions): WWDLW
The Wales international, who suffered the problem during the opening-day defeat to Liverpool, has struggled with similar issues in the past, and it seems as though he will not be back on the pitch until after the international break next month.
Olivier Giroud is yet to start a game for the Gunners this season, and he may have to wait longer for the call as he is a doubt with a toe injury.
Wenger has a selection dilemma in midfield as Xhaka has been in form - scoring twice in his last two games - but Francis Coquelin could provide a bit more sturdiness in Saturday's game.
Following Fabregas's brace in midweek, the Spaniard may find himself in the first XI against his former club.
Arsenal possible starting lineup:
Cech; Bellerin, Mustafi, Koscielny, Monreal; Xhaka, Cazorla; Walcott, Ozil, Iwobi; Sanchez
Chelsea possible starting lineup:
Courtois; Ivanovic, Luiz, Cahill, Azpilicueta; Kante, Matic; Willian, Fabregas, Hazard; Costa
Head To Head
Chelsea are unbeaten in their last five visits to the Emirates and have conceded just one goal in that time. In fact, they have not lost to their North London competitions in nine Premier League matches following six wins and three draws.
Goals have been hard to come by for Arsenal in their clashes with Chelsea as they have failed to strike the net in their last six league meetings.
Discipline has also been an issue in the past as the Gunners have had four red cards issued in their last five league head to heads.
We say: Arsenal 1-1 Chelsea
The Blues got the better of Arsenal last season as they won 2-0 and 1-0 in the Premier League, but Wenger's men are in better form heading into Saturday's contest. They have won their last three top-flight fixtures, but the North London outfit are known in recent years to sometimes crumble against top opposition. Wenger does not have the Mourinho rivalry to contend with this weekend, but on the pitch, it could be an explosive affair. A share of the spoils is a likely result.