Arsene Wenger declared Arsenal's dramatic stoppage-time victory over Barclays Premiership title-race leaders Manchester United would "open it up for everybody".
The Gunners came from behind to ensure their unbeaten record at the Emirates Stadium remained intact - and deny the Red Devils the chance to extend their lead at the top of the table to nine points over Chelsea, who lost 2-0 at Liverpool on Saturday.
Substitute Robin van Persie cancelled out Wayne Rooney's early second-half strike with just seven minutes left, before captain Thierry Henry powered in a header to snatch victory deep into stoppage time.
Despite their defeat in north-London tonight, United remain well clear of Chelsea - and some 12 ahead of Arsenal, who are fourth.
Wenger felt the desire of Sir Alex Ferguson's men to try to run down the clock came back to haunt them. The Arsenal manager said: "They wanted so much to kill the time that it turned against them as well, because they lost a bit of their game.
"With 10 minutes to go Manchester United were maybe champions, but at the end of the game you cannot say that. "It will open it up for everybody. "For us and Liverpool a little bit less, but you never know."
Wenger, though, maintains United remain in the driving seat to break Chelsea's grip on the Premiership crown. He said: "Of course Manchester United will still be strong challengers for the title. "This will be a big disappointment for Manchester United - but do not expect them to crumble because of it. "But it is good for the interest of the Premiership, because everybody still has a chance.
"We have maybe less than all the others, but will just try to fight to win every game." The Gunners boss feels his men will have taken a great deal from snatching victory, which extended their fine recent form of just one defeat in 13 games.
Wenger said: "We were a bit nervous at the start and gave them a bit too much respect. "It took us time to get into the game. "In the first half, Manchester United were more mature. Then we took over in the second half, but they scored on the break.
"It was a test of character, resilience and togetherness, qualities which are very important for the development of the team. "This team is developing into young, hungry lions, lead well by Henry."
The Gunners take on north-London rivals Tottenham in the semi-finals of the Carling Cup next week, and are also in the fourth round of the FA Cup as well as the knockout stages of the Champions League.
Wenger, though, looks set to be without striker Van Persie for some time after an X-ray confirmed the Dutchman had sustained a "partial fracture" to his foot, suffered when scoring the goal.
"Now we come to a period where every game matters," the Arsenal manager added. "Our target is to sustain that run."
United boss Ferguson, meanwhile, fully expects his men to swiftly bounce back from what was only their third defeat of the Premiership season - two of those at the hands of the Gunners.
He said on MUTV: "Teams at the top always drop points on the run-in. It happens - but how you cope is important. "Only true champions come out and show their worth - and I expect us to do that."
Ferguson vowed his side would learn from their late capitulation - and use it as a spur for the rest of the campaign. "When I look at it we have some important away games to come and this will be good for us - we won't be making the same mistake," the United boss said earlier to Sky Sports.
"We lost two goals from a position I did not think we would. "At this moment in time we are so disappointed. "We have a game less (to play) and are a goal better off (than Chelsea). So it is not all doom and gloom."
