While the Gunners currently sit an incredible eight points clear of the reigning champions, a result either way on Sunday could prove more pivotal for Arsene Wenger's side than it could for David Moyes'.
The Gunners have struggled in recent years at Old Trafford, with just one win in 11 outings.
However, all three of Wenger's title-winning sides have had crucial results at the Red Devils' home.
In 1998 - Wenger's first title - Marc Overmars scored a late goal to give the North London side victory and give Arsenal the edge over Sir Alex Ferguson's table-toppers.
Four years later, when Arsenal again won the double, a Sylvain Wiltord goal sealed the title at the home of their closest rivals for the title.
And whilst the famous scenes post-game in their 2003 game remain memorable, a hard-fought scoreless draw in Arsenal's invincible season, set the tone for their stubborn resilience - albeit with a hint of luck as Ruud van Nistelrooy missed an injury time penalty.
And should Wenger's current side - 10 years on from the famous Invincibles - show the same grit and determination at Old Trafford as their predecessors, the win, or indeed draw, could prove instrumental.
That day in 2003 will live long in the memory for the way Arsenal bombarded van Nistelrooy immediately after his penalty miss, but what is more important is that the Gunners claimed a draw despite being down to 10 men - Patrick Vieira seeing red earlier in the game.
A similar result on Sunday could well spark the start of something special for Wenger's current crop.
They've already navigated tough ties against Liverpool and Borussia Dortmund and a third big result in a week would show punters this team mean business.
But there is a flip side.
The year after their well-earned draw at Old Trafford that sparked a title win, they again visited Manchester, playing arguably better football.
Looking to make it an unbelievable 50 games unbeaten, the Gunners were defeated 2-0 in controversial fashion.
The loss hit Arsenal hard and frankly, the red side of North London hasn't looked the same since.
Similarly, their embarrassing 8-2 defeat there two seasons ago seemed like the beginning of the end for the Gunners.
Another loss on Sunday and they lose more than a points gap on United and the chasing pack - they lose a mental advantage.
A negative result will see the Gunners branded nearly men before the season has even hit Christmas.
Yet a win - or indeed even a draw - would complete a remarkable week.
Holding their own against the Champions in their own back yard would add yet another boost of confidence to Mesut Ozil inspired Arsenal, and fire the Gunners to what could be a 14th title.
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