Sir Alex Ferguson watched his Manchester United side beat Arsenal at the Emirates and then invited Arsene Wenger to go to Stamford Bridge next Sunday and "batter" Chelsea.
United's 3-1 win against the Gunners cut Chelsea's lead at the top of the Barclays Premier League to just one point.
It also saw Wayne Rooney notch his 20th league goal of the season and his 100th overall in the Premier League.
Ferguson singled out Rooney as the main difference between the teams and also insisted he was confident the striker was happy at Old Trafford.
Ferguson said: "Rooney was unbelievable. He was the key player and they couldn't handle him.
"He's very happy at the club. He's popular among the players and couldn't be a better lad. He's down to earth and won't change because that's who he is.
"That's refreshing in this day and age of celebrity-type footballers with lots of money, but he never changes when some people do change with success."
Rooney still has more than two years on his Old Trafford contract but has been linked with interest from Real Madrid and United are thought to be preparing a new improved deal.
Ferguson said: "I'm sure that David Gill (United chief executive] is working with (Rooney's agent) Paul Stretford. Hopefully something does happen."
Rooney's goal came after a sweeping move involving Nani. Park Ji-Sung added another after Nani had set United on the way with a brilliant solo run which culminated in his chip being palmed into the net by Arsenal goalkeeper Manuel Almunia.
Arsenal scored a late consolation when Thomas Vermaelen's shot was deflected home off the unfortunate Wes Brown.
But while the Gunners looked desperately short of a striker in the absence of the injured Robin van Persie, manager Arsene Wenger insisted he had no intention of doing business before the transfer window shuts.
Wenger said: "It's difficult to accept but easy to explain because we were poor offensively and defensively. We delivered an off-the mark performance and that is why we were well beaten. We were naive."
Wenger admitted it was a major jolt to their title ambitions, adding: "It was not just Rooney who gave us problems. We gave them too much room everywhere. Rooney took advantage of it.
"We conceded two goals from a corner for us and it turned into a goal for them. It was our positioning that was wrong.
"It is a massive blow and a massive disappointment but we have to recover from that. It is part of top Premier football. The players are really down."
Wenger pointed out that United had taken one point from their last six games against clubs in the top four and that the victory was their first away from home against a top four team in two seasons.
He said: "They played well and we were completely not at our level. There are some mental reasons.
"Next Sunday we have to focus on delivering a different performance. Today we were never close in our marking. You do not win big games like that.
"We need to deliver something special now to stay in the race. I am conscious of that."
Ferguson, meanwhile, is banking on the defeat producing a spectacular backlash from the Gunners, who he insisted could still win the title.
He said: "That was a great performance by us. I'm very pleased. It's at this time of year that you need to kick on.
"The run-in is always a difficult period. We've handled it in the past and I trust the players to handle it again.
"We need Chelsea to drop points, but Arsenal aren't out of it yet. I hope Arsenal go to Stamford Bridge and batter them next Sunday."