Why Arsenal manager Arsène Wenger must be sick of the sight of brilliant Manchester United striker Wayne Rooney
No wonder David Moyes smiled as he triumphantly walked to the home dressing room, with Old Trafford cheers ringing in his ears. The table had turned.
And the Manchester United manager knew it.
Manchester City are the crisis club now. Not United, on a roll and a serious danger to the rest, none more so than Arsenal, who may live to regret their lacklustre performance yesterday.
This was Arsenal's big chance to knock United out of the title race.
Entering the contest, which never reached the heights we'd hoped for, the incentive was there for the Gunners. An away victory would have moved them 11 points ahead of United.
Too much to claw back.
In the past the Red Devils have shown remarkable powers of recovery to win championships, but that was during Sir Alex Ferguson's reign.
This is a different time, and even though under the management of David Moyes they had won their previous two league games, doubts persisted about a title charge among the United faithful prior to kick-off.
There won't be so many today.
Those victories over Stoke and Fulham were crucial in steadying a ship that looked as though it would sink without its celebrated and experienced captain, but overcoming a major rival in the league was what Moyes desperately needed.
And fresh from beating Arsenal 1-0, there will be a sense that the club can at last set sail for a 21st title. Instead of being 11 points adrift, United are just five points away from top spot.
The confidence they'll gain from Robin van Persie's winner should ensure the champions will be contenders from here until May.
Moyes, of course, still must prove he is worthy of the manager's job and the players must prove they can win a crown without Ferguson.
It appears as though Wayne Rooney wants to prove that more than anybody. He was magnificent yesterday. Full of fire, passion and skill.
Van Persie's intelligent headed goal in the 27th minute was the defining moment, but it was Rooney who was the best player on the pitch, crossing from a corner for the Dutchman to score and constantly providing a threat to the Arsenal rearguard. They found it hard to live with him.
A bug had gone round the Arsenal squad leading up to the game, which meant Per Mertesacker and Tomas Rosicky missing out. By the end of the encounter, the rest of Arsene Wenger's team were sick of the sight of a rampaging Rooney.
While United should go from strength to strength, it'll be intriguing to see how Arsenal react to this defeat after the international break.
After a disappointing first-half, they came into the fray more as the match progressed, but still lacked the dynamic cut and thrust which had taken them to the top of the table.
Aaron Ramsey, player of the season to date, was ineffective. Ditto Mesut Ozil beside him.
Bar the brilliant Rooney, United were more solid than spectacular. Much like Ferguson's teams down the years, they got the job done.
With City losing away again, there was a feeling inside Old Trafford that all was right with the world for the first time since Sir Alex left the dug-out.
City, who on the road are about as useful as a car without wheels, are down to eighth. United are up to fifth. With another title threat. Chelsea, only drawing, this was the best weekend of the season for United.
Moyes, growing into his role, will feel there is better to come.