An own goal from Craig Dawson has handed Manchester United victory over West Ham United.
The Red Devils dominated the opening stanza but were unable to capitalise on their chances.
Marcus Rashford missed a free header from inside the six yard box, while Lukasz Fabianski denied Mason Greenwood with a fine save onto the post.
Ole Gunnar Solskjaer's side didn't have to wait long into the second-half to break the deadlock.
Scott McTominay turned away to celebrate after Bruno Fernandes' corner ended up in the back of the net.
But replays showed McTominay had missed the ball, which instead hit Dawson and flew past Fabianski.
The goal spurred an ultra-defensive West Ham into action, with David Moyes bringing on Manuel Lanzini and Said Benrahma.
Tomas Soucek came close to equalising but was blocked by Luke Shaw, who helped United keep a fourth successive clean sheet in the league.
Bruno Fernandes was denied a stunning goal by an outstretched Fabianski, but ultimately United held on for all three points to move back into second on the table.
West Ham missed out on a chance to draw level on points with fourth-placed Chelsea, but the Hammers have a game on hand to their London rivals.
"As expected, they are always going to make it hard for you," Solskjaer said after the game. "We could have been more comfortable towards the end as we had a few decent chances to finish it off. We like to make it hard for ourselves!
"It's about not giving them turnovers all the time. In the first 15 minutes we gave the ball away every time we attacked. It was a good set-play and we scored. You have to not open up stupidly as you know they are a threat on the counter-attack so we kept composed and organised.
"We created massive opportunities but the final pass or shot wasn't good enough. Could have been two or three easily. But then it could have ended up in our net at the end as they are a threat.
"We know West Ham are challenging to get in the top four so it was a big result and we kept a clean sheet again. The experience and confidence will come. Big week - Europa League and FA Cup - so we're looking forward to it. Hopefully get a few players back and put a good performance in."
