The hosts threw everything at West Brom in the closing stages, but were unable to find a breakthrough that would have delayed City's title confirmation until at least Wednesday when United take on Bournemouth.
City are worthy champions, having been head and shoulders above their neighbours as well as the rest of the league this season. "We're going to Shrewsbury", they sang early in the game.
"I won eight titles and I am not [over] the moon because I won against Manchester City", he added. He has a very good squad, but he needs to get more from it. Paul Pogba needs to significantly improve, as does Alexis Sanchez.
It was an ineffective performance from United and Pogba, who had inspired the brilliant 3-2 comeback victory against City last weekend.
However, the United manager also gave a strong defence of his own record, listing some of his achievements with Chelsea, Real Madrid and Porto, after being asked how United could expect to overhaul Pep Guardiola's team next season.
"I trust in my work, that is for sure - I have no reason not to trust", he said.
Married woman gang-raped in Uttar Pradesh village
Mlilo spent her first night in a dirty cell with 15 other women, a dirty toilet and no tap to drink water from. The girl was kidnapped and raped over a period of 10 days until she managed to flee from teh accused.
Mourinho said: "We were masters in complicated football, everything was complicated".
But a drop in form allowed City to race ahead, leaving the rest of the Premier League in their wake.
At least West Brom won't be around next season to win at Old Trafford, but the team which had won only once since August are the type of side title contenders should be beating out of sight, not tripping up against at home.
"We couldn't play fast, we couldn't think fast, everything was complicated".
It was a kind of collective neurosis which unfolded, and it was another example of these players lacking believe themselves and Mourinho lacking a clear attacking plan. The Portuguese gaffer needs to rethink his ways if he wishes to win silverware with the club and live up to the expectations of the United faithful.
"They won because they were the best team, they lost only a few points".
"The best way to achieving that is to aim for stability at training level, during the working week, and from what I have seen in the past two or three weeks I am really happy with him".