The sight of Robin van Persie emerging back on to the pitch after the final whistle, despite being substituted showed two things.
The first was that Robin van Persie was happy to beat his former team and that he no longer feels sorry for them. He'll hate to see Arsenal win the title as he languishes at Manchester United and saw this win as further confirmation that he made the right decision.
The second; it showed just how much this victory meant to Manchester United.
In the same fixture last season, the Red Devils played Arsenal off the park in a dominating performance. The 2-1 scoreline paints a different picture but for those who watched the game, you would think the two teams were in a different division. Arsenal were inferior.
United fans and players alike saw the win as an expected formality, but that is no longer the case.
It seemed the win last night was a marquee moment in United's season. Arsenal hadn't gone to Old Trafford with so many expecting a Gunners victory in years.
But the reality is, the Gunners were at the end of a hectic two weeks that saw them play Chelsea, Liverpool, Borussia Dortmund and Manchester United. They were exhausted and had very little left to offer.
Despite the fact that Arsenal's stars were far from their best, Manchester United could only score one very, very lucky goal before relying on Nicklas Bendtner's incompetence to keep their lead intact.
Had the ball not hit Van Persie's shoulder, or if Per Mertesacker had been there to defend the near post as usual, that goal would not have gone in and Arsenal would have got the draw they deserved.
Despite losing, the game delivered many positives for the Gunners.
It confirmed that the defending champions are not the confident force they once were.
They struggled to break down an Arsenal side that was still recovering from a historic win away to Borussia Dortmund whilst United were rested from a meek 0-0 draw to Real Sociedad.
David Moyes was lucky to face Arsenal at the right time - at the end of a hard run of fixtures. Had they been facing the Gunners after the international break it is likely the scoreline would be reversed.
So even though Manchester United have closed the gap on Arsenal to five points, they aren't back in the title race. It does alleviate fears that they could miss out on the top four, but it does not mean they'll be top of the pile come May.
If they struggled to beat an Arsenal side battered by tough fixtures and an injury crisis, they will not beat the Emirates outfit, Chelsea or Manchester City to the title.
They may have got the three points, but the game exposed all of the flaws that will prevent United from retaining their Premier League crown.