One of the most eagerly anticipated fixtures in the Premier League calendar takes centre stage on Sunday afternoon when Arsenal host Manchester United at Emirates Stadium.
With the Gunners currently just three points behind leaders United, a victory for either side would represent a huge boost in their respective bids to produce strong title challenges.
Arsenal
Arsene Wenger celebrated the 19th anniversary of becoming Arsenal manager this week, but instead of cakes and champagne, it has been a turbulent few days for the Frenchman, who appears to be in the middle of his annual tradition of coming in for criticism from all corners.
In truth, very few Arsenal supporters would suggest that Wenger does not deserve at least some of the criticism he has received. After starting their Champions League campaign with a defeat to Dynamo Zagreb, the Gunners were beaten again in midweek as they twice fought back from behind before losing 3-2 to Olympiacos in North London.
It leaves Arsenal facing a mountain to reach the knockout stage, and most of the responses to the defeat have been centred on Wenger's team selection after he decided to leave Petr Cech on the bench to hand a start to David Ospina, whose mistake was key in handing the Greek visitors their first win on English soil.
Wenger was quick to come out in defence of his team selection, but his supporters were quiet this week as many questioned the decision to leave Cech out after the Gunners had waited so long to sign a dependable, world-class goalkeeper.
The Arsenal boss always seems to face at least one difficult spell in the season, but patience appears to be wearing thin after the summer optimism from supporters who believed that this squad was capable of challenging in all competitions for the first time in many years.
Despite the frustration which surrounds their Champions League campaign, Arsenal bounced back in the Premier League last weekend by thrashing Leicester City 5-2 thanks largely to a hat-trick from Alexis Sanchez, whose return to form could be crucial as Wenger looks to answer his critics once again.
Sitting three points behind the leaders after seven games is a respectable start, but with just one home league win to their name so far, the club's supporters are desperate to see a performance to convince them that this squad is strong enough to challenge.
Recent form: WDWWLW
Recent form (all competitions): WLLWWL
Man Utd
As Sunday's opponents deal with the fallout of another shock defeat in the Champions League, the feeling in the United camp is that confidence continues to grow as Louis van Gaal aims to return the club to the elite both at home and abroad.
Nothing less than a title challenge would be accepted by the club's army of supporters after Van Gaal steered the team back into the top four last season, and the early signs suggest that there is every reason to be cautiously optimistic about their chances climbing back to the top of English football.
A comfortable 3-0 win over Sunderland last weekend was enough to take United to the summit as Manchester City faltered once again, before they recovered from their own defeat on the opening Champions League matchday by beating Wolfsburg at Old Trafford in midweek.
Perhaps most surprising of all is the fact that United have managed to make such a promising start to their title pursuit with many onlookers claiming that they are not playing well, and although Van Gaal is unlikely to ever listen to the opinions of his critics, even he must believe that there is more to come from his squad.
A settled squad with strength in depth is certainly the difference this season, and after just one loss in their opening seven league games, the challenge is for United to prove their title credentials as they prepare to meet Arsenal, Everton, Man City and Crystal Palace in October.
Wayne Rooney ended his drought in the league last weekend, while Anthony Martial continues to impress in the early stages of his career, and scoring three goals in four of their last six games is further proof that the squad are beginning to click into the final third to add to the defensive resilience which Van Gaal is eager for his side to display every week.
Reaching the top of the table for the first time since Sir Alex Ferguson's departure in May 2013 is a good start, but Van Gaal knows that only success over this tricky period will prove to the fans and his doubters that there are even bigger achievements to come.
Recent form: WDLWWW
Recent form (all competitions): WLWWWW
Team News
The Gunners were dealt a blow this week with the news that Laurent Koscielny will be out for three weeks with a hamstring injury, which means that Per Mertesacker is set to return to partner Gabriel in the centre of defence.
Arsenal are also without Mikel Arteta and Mathieu Flamini due to injuries, but Francis Coquelin is expected to shake off a knock to start in the centre of midfield.
The key selection issue for Wenger will be whether he chooses to recall Olivier Giroud or keep faith with Theo Walcott, who has netted 12 goals in his last 13 league starts.
Michael Carrick has recovered from the minor injury which kept him out of the midweek win over Wolfsburg, and Van Gaal must choose between him and Bastian Schweinsteiger to partner Morgan Schneiderlin in midfield.
Ander Herrera and Marcos Rojo remain doubts for the visitors, while Antonio Valencia is set to retain his spot at right-back as Matteo Darmian prepares to once again play on the left side of defence in the absence of Luke Shaw.
Arsenal possible starting lineup:
Cech, Bellerin, Mertesacker, Gabriel, Monreal, Coquelin, Cazorla, Ramsey, Ozil, Sanchez, Walcott
Man Utd possible starting lineup:
De Gea, Valencia, Smalling, Blind, Darmian, Schneiderlin, Carrick, Mata, Rooney, Memphis, Martial
Head To Head
Van Gaal claimed his first away win as United boss when a Kieran Gibbs own goal and a strike from Rooney helped them earn a 2-1 victory at the Emirates Stadium last November.
The two sides settled for a draw in the reverse fixture at Old Trafford, but there was success for the Gunners last season when former United striker Danny Welbeck secured a 2-1 win in the quarter-finals of the FA Cup.
Since the Premier League's inception, United have never gone five games without a defeat at the home of Arsenal but they can achieve that feat by avoiding defeat at the weekend.
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Hit play below to see what the Sports Mole Sofa had to say about this encounter:
We say: Arsenal 1-1 Manchester United
Despite United being top, it still feels like these two sides are facing a battle to prove to their critics that they are genuine title contenders this season, but a win for either team would hand them a huge boost at this stage of the campaign. Arsenal come into the game on the back of a disappointing Champions League defeat and they will be desperate to bounce back against a confident United squad. It is difficult to pick a winner, and a moment of magic could be needed. A draw would not be the worst result for the two managers.