Arsenal boss Arsene Wenger has conceded that defeat at Manchester United could have been "decisive" as far as their title chances are concerned.
Wenger celebrates Adebayor's goal
However, the Gunners won 1-0, thanks to a late goal from Emmanuel Adebayor.
"A loss could have been decisive but this win reinforces the belief that we are a very strong side," said Wenger.
"I would never have thought that our challenge would have been over if we had lost but psychologically it might have been difficult for the players."
Wenger added: "We controlled the game and created chances. We always looked good technically. Everyone in the team played well, gave everything and showed quality.
When you make mistakes in midfield they are as good as anybody in making you pay
Man Utd captain Gary Neville
The Gunners had a great chance to take the lead earlier in the match but Gilberto had his penalty saved by Tomasz Kuszczak.
The Brazilian slipped as he took the kick, making it easier for the keeper to save the effort.
"I've seen a lot of big players miss penalties," said Gilberto.
"Afterwards a lot of my team-mates came over and gave me support. It helped me keep calm.
"A lot of reports said that we were out of the title race but those people are completely wrong."
Meanwhile, Manchester United skipper Gary Neville said Arsenal made his side pay for their sloppy play.
"We are disappointed. When you make mistakes in midfield they are as good as anybody in making you pay," he said.
"Our passing wasn't good and we looked tired. We gave the ball away too many times. We would have accepted 0-0.
"We had two or three clear-cut chances, but didn't take them. They had three good chances too."