Manchester United manager Jose Mourinho hopes to have silenced the critics, holding a finger to his lips after beating Tottenham and telling the doubters to calm down.

Second hosted third on a damp afternoon at Old Trafford, where a cagey clash of the Premier League title contenders looked set to end all square.

However, Mourinho's decision to replace Marcus Rashford with Anthony Martial - a change jeered by some fans - paid dividends as the substitute raced onto Romelu Lukaku's flick-on to fire United to a 1-0 win.

The Portuguese held a finger to his lips at the final whistle and muttered directly into the camera after their most important win of the season so far.

"Some people speak too much," Mourinho said of the gesture. "You know, calm down, relax. Relax a little bit.

"Don't speak too much - speak, speak, speak. You know, relax."

Asked if it was aimed at the critics he labelled "Einsteins" or journalists, he said: "Yeah, relax a little bit. Don't be so nervous, don't be so excited. Calm down a little bit.

"The opposition bench did their job, super-correct. It has yet to arrive, the match where myself, Mauricio (Pochettino), my staff and his staff, have a problem.

"We played against each other so many times since Spain, and we have a really good relation(ship).

"We lose, we win, I don't know if we draw and we are always correct with each other.

"And once more I'm even happier because we beat a very good team. I like the team very, very much."

It certainly felt like an important win given how well Manchester City have started the season.

Martial again made a telling impact as a substitute, scoring his fourth Premier League goal from the bench this season - more than any other player.

Lukaku hit the post in the minutes leading up to the winner but things could have been different had Dele Alli turned a fine Christian Eriksen pass home from close range just before.

"Very disappointed," Spurs head coach Mauricio Pochettino said. "It is very painful for our players, for everyone.

"I think it was an even match. We lose in an action that should have been fixed before. I think it's very painful but that is football and I feel very proud.

"The effort was fantastic. The performance can always be better, but I think we compete and we fight a lot.

"Yes, disappointed but now keep going, move on."

Leading man Harry Kane's absence was certainly felt at Old Trafford, with Spurs hoping to have the striker back from a hamstring injury to face Real Madrid in the Champions League.

"I said before the game to everyone that always you are going to miss your main striker - and Harry Kane is one of best strikers in the world, of course," Pochettino said.

"But it is not an excuse today. We didn't lose the game because Kane wasn't here.

"It is a collective sport and always you must adapt when some player is not fit to play.

"I am happy with the performance from everyone and I think we deserve more than zero points.

"We'll see in the next few days if he can arrive and will be at a high level and fit to play Real Madrid.

"We need to assess him tomorrow, and after tomorrow and then make a decision."