Romelu Lukaku has wasted little time demonstrating why he became the club's most expensive signing over the summer and, on this evidence, it is shaping up to be a season of rich promise for Jose Mourinho's team.
The Red Devils have spent big once again this summer bringing in Victor Lindelof, Romelu Lukaku and Nemanja Matic. But there can be few positives taken from this game for the travelling support, who have a long trip home to London after watching their side completely rolled over.
Mourinho played it all down, however, saying: "Last season we were also top of the league in the first match and we finished sixth so this means nothing".
"We have reasons to be optimistic", Mourinho said, before adding: "My feet are on the ground and I am calm".
"I don't think it's good enough to say "they're going to get back into fourth".
"I never thought it was possible unless something special was happening and his agent told me we could have him and we were very happy with that".
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West Ham have a few key players missing for this match, with Diafra Sakho, Andy Carroll, Cheikhou Kouyate, and Manuel Lanzini all out, and the duo of Aaron Cresswell and Sofiane Feghouli in varying degrees of doubt.
Lukaku was virtually unplayable at times and he doubled United's advantage in the 53rd minute with a bullet header from Henrikh Mkhitaryan's free-kick. The Red Devils are off to Swansea next week, while West Ham stays on the road and faces Southampton. He likes the team and the team likes him. As our Peter Goldstein noted before the start of the season on Manchester United's lack of set-piece goals: 'Last year they managed a mere seven, with only Sunderland recording fewer.
"It's nice for [Alvaro] Morata to score, nice for Wayne Rooney to score and Lukaku and [Alexandre] Lacazette, it's always nice for that confidence".
Mourinho knows how to win the championship, but his players must be ready for that task. "But today was very good and he was very effective, with the first goal especially".
Slaven Bilic will be relieved that his side are only down 1-0, and will be encouraged by the last moment of the first half, as the Hammers best move came before the whistle. Everything he does is neat and tidy.