Arsenal boss Arsene Wenger has warned Manchester United's title rivals that the Premiership leaders will not crumble, despite Sunday's defeat.
Thierry Henry's injury-time winner gave the Gunners a 2-1 win over United but Wenger said: "They 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 Premiership because everybody still has a chance."
Wenger paid tribute to his "lions" for fighting back from a goal down to beat United.
"We won by never giving up," he said.
"We began nervously and United started with maturity but I knew after the break we would have a go.
"They got their goal with their only chance of the half but we fought back because we have lions in our team."
The Frenchman added: "We needed to be direct with our play, although I think we were direct a little too often.
"Only true champions come out and show their worth after defeat- and I expect us to do that"
"But I think we mixed our play well and there was so much spirit in the squad."
The only thing to mar Arsenal's victory was the news that striker Robin van Persie had broken a bone in his right foot while celebrating his equaliser - and he is set to be ruled out for six weeks.
United boss Sir Alex Ferguson expects his side to bounce back from their third loss of the Premiership campaign.
"Teams at the top always drop points on the run-in. It happens - but how you cope is important," he said.
"Only true champions come out and show their worth - and I expect us to do that."
Ferguson said he was disappointed with the manner in which his side lost the game.
"We defended well - they resorted to long balls and we were coping great," he stated.
"Then we lost two goals from positions we didn't think we would lose goals.
"We have some important away games and the team will be back to winning ways very soon. Rest assured, we won't lose like that again."
United are six points clear of nearest rivals Chelsea in the Premiership table.
Ferguson added: "We have a game less to play and are a goal better off than Chelsea following their 2-0 defeat at Liverpool yesterday. So it's not all doom and gloom."