Afterwards, the Arsenal manager Arsene Wenger conceded that his team would not be champions come May. "Yes," he said simply when asked if Chelsea could not now be caught "There is a small chance for Manchester United but, for us, it is over."
His opposite number, Sir Alex Ferguson, agreed but despite the import of those declarations it will be the squaring up of Keane and Vieira, clearly caught on the television feeds, that will dominate. "I don't want to go into too much detail but Patrick Vieira is 6ft 4in
and he starts having a go at Gary Neville," Keane said later. "So I said, `Come and have a go at me'. It's as simple as that. If a player wants to try and intimidate some of my team-mates then let's have a go at some of the other players. They think Gary Neville's an easy target. And I'm not having it."
It was yet another ugly incident in the recent history that has plagued these two clubs and will not have pleased the FA's new chief executive Brian Barwick, who was among the spectators and who had called for calm beforehand.
The aggression typified an unforgiving encounter which the referee Graham Poll did well to control. Nevertheless, he dismissed Mikael Silvestre - for butting Fredrik Ljungberg - and issued six yellow cards. The contest did not reach the violence of the autumn meeting at Old Trafford, and previous matches, but there was a malignant air.
Vieira denied having threatened Neville but admitted having had "a talk" with Keane. "Gary Neville is a big boy and can handle himself," Vieira said. "I did not try to intimidate anybody else and I don't want to talk about it."
However, Vieira also conceded that, with his side now pushed into third place and 10 points behind Chelsea, having played a game more, their title challenge has been extinguished. "That is the way it is," he said. "Chelsea are doing fantastically well."
Wenger blamed the defeat on defensive errors and said that they had been the story of his team's season. "The players do not have the confidence at the back that they had last year. They [United] did not look like they had to work hard for their goals."
He said that his players' confidence had to be rebuilt. "It is demoralising but we have pride and the pride of a football player is to do as well as you can."
Ferguson spoke of his delight at the victory, made all the sweeter given the personal enmity. He also said: "I heard from the boys that Patrick Vieira in the tunnel threatened some of the players. So he was well wound up for it.
"I think we said it before the game, both managers, that whoever lost would have no chance now.
"We came from behind twice and that shows the determination from my team. We showed that tonight. It was a fantastic performance from them. I think we have the mental strength."
Ferguson also claimed that there had been "a lot of play-acting going up. But my team stood up to that."
He did concede, however, that it would be hard to catch Chelsea, who could reopen an 11-point lead by beating Blackburn Rovers tonight.Reuse content