Sir Alex Ferguson warned Manchester United's title rivals his team have the look of English Premier League champions heading into the final seven games of the season.
The league leaders fought back from two goals down against West Ham to win 4-2 at Upton Park, with Wayne Rooney scoring a hat-trick to turn the game.
"We played like champions," said United manager Ferguson. "We kept our head up and didn't lose faith in our ability. That was a great, great boost for us in that respect.
"We dominated the second half and deserved to win, it was a real championship performance as far as I'm concerned. Arsenal have games in hands and it could go to goal difference but I somehow don't think so.
"I think we have to win our games but it was a great boost getting that result. We have four home games, three away, and the message is to go and play, and they did.
"You can count the games down one by one. It ends up you run out of games and hopefully we're there."
Mark Noble's two penalties earned a lead for the Hammers, but they also felt United captain Nemanja Vidic should have been dismissed for fouling Demba Ba when the striker was through on goal.
"I didn't see it but he was the last man so if it was a foul it was a red card," said manager Avram Grant.
Even Ferguson acknowledged Vidic had been fortunate to stay on.
"He could have been sent off for the free-kick when he was through, maybe he got a lucky break," he said.
Rooney took advantage in the second half when he curled home a free-kick and also tucked away a neat finish, his 100th league goal for United.
His hat-trick came from the penalty spot but the England striker's foul-mouthed reaction when he celebrated led to an on-air apology from broadcasters.
Rooney admitted he was caught in two minds where to place his spot-kick after practising against Robert Green during the international break with England.
"I've been working on penalties with Greeny all week, and it was just as well," said Rooney. "I didn't know what to do so I stuck to what I was doing all week. Greeny maybe thought I was going to change.
"I'm delighted. It's a difficult place to come but we took encouragement from the first half, we were in good areas and were just not taking our chances. We knew if we got the next goal we were capable of scoring more and thankfully that was the case.
"The manager just said keep going, the next goal is the most important. Thankfully it fell for us and then we managed to control the game and take our chances."
Javier Hernandez added the fourth goal after tapping home Ryan Giggs' cross. Giggs felt the result sent out a message to United's title rivals.
"It sends out a message that we just don't give up, no matter what the score is in the game," Giggs said.
"We're grinding out results. Some games we've been grinding out results when we've not been at our best. Hopefully with seven games to go we can keep doing that."
Grant is still optimistic about West Ham's survival hopes.
"I think we can do it because we are in good shape at the right time. The other games are important. They are ready for any situation which we saw this season.
"There were a lot of positive things, even against Manchester United we showed we have a good team. In the first half you wouldn't know who is top and who is bottom but football is two halves and it was too easy for them to control the game," he said.