Avram Grant conceded his team had been well beaten in the end in the 4-0 loss to the Barclays Premier League champions-elect on Saturday.
Although two first-half penalties from Mark Noble had put the Hammers firmly in the driving seat at half-time, Sir Alex Ferguson's men roared back after the break. Inspired by Wayne Rooney, who was to score a hat-trick, Manchester United stepped up several gears to score four unanswered goals.
When asked to summarise Saturday as a whole, Grant said: "That is the sign of champions. They won the game but we are only thinking about ourselves. We played the first half very well. For a long time, I haven't seen a team dominate so good against Manchester United. The first half we were up two nil and then the second half we didn't play so well."
Noble's two penalties were won via Carlton Cole, the first seeing Patrice Evra handle under pressure, the second when the No9 was brought down by Nemanja Vidic. In the latter incident, the Serbia defender was considered lucky by many to escape a red card as he appeared to be the last man, but Grant would not be drawn into whether that was a pivotal moment in the game.
Similarly, he was tight-lipped about the handball given against Upson that allowed Rooney to put Manchester United in front 3-2, but added "the players were very disappointed". By then, Rooney had scored with a tremendous central free-kick 20 yards out and a superb solo effort that Robert Green could do little about.
Half-time substitute Javier Hernandez wrapped up a convincing away win, and Grant recognised that their attacking verve told.
"They are a good team. The second half they didn't have anything to lose so they played with [Ryan] Giggs at left-back and had a lot of quality. We gave them the space and Rooney hurt us."
Grant will have a full week now to focus the players' minds on the trip to Bolton Wanderers next Saturday, and was still looking for positives despite the team dropping back into the bottom three.
"The players know it will go to the end of the season . They did their best to take the points and we wanted to. We did everything but the players are ready for any situation as we have shown this season. We have had good momentum.
"There are a lot of positive things. The players saw that even against Manchester United when they are doing the right things, we have a good team. In the first half at times you didn't know who was at the top and who is at the bottom. But football is two halves and we know we needed to complete the job. It was too easy for them to control the game."