Manchester United are doing what is required: winning to ensure those chasing do not gain ground, this edgy victory following that of third-place Leicester’s earlier on Sunday. Ole Gunnar Solskjær’s side were hardly a whirr of irresistible football but they will not care. In squeezing Craig Dawson into heading past his own goalkeeper, Lukasz Fabianski, for the winner, the home side also kept the Hammers nine points behind them in fifth in the challenge for a Champions League berth. The manager characterised this week as “massive” due to the match being followed by Thursday’s trip to Milan for the Europa League last-16 second leg – the tie is poised at 1-1 – and Sunday’s FA Cup quarter-final at Leicester. “We are starting to build some momentum - have opened the gap further to West Ham which was important,” Solskjaer said. “We want to improve on last season – finish second, reach a final, so this week was always going to be massive.” Manchester United are unbeaten in 13 games and have allowed only one goal in their last six. “If you have clean sheets you have a good foundation,” the manager said. He was able to select Marcus Rashford after he had been an injury concern, while David Moyes was unable to call on in-form Jesse Lingard against the player’s parent club. Moyes will have been pleased with the opening as his side applied pressure. It culminated in a corner won by Michail Antonio. Mark Noble swung this in to the far post, Aaron Wan-Bissaka fell, as did Dawson, in a mini-pileup of players, but the referee, Martin Atkinson, saw nothing foul. This was about as good as West Ham were going forward as Solksjær’s side dominated. First came a measured sequence in which Rashford moved along a right channel and fed Mason Greenwood and when he tapped inside, Luke Shaw received it, rolled over a cross, and there was Greenwood to attempt a backheel. Twice when Greenwood received the ball, loose distribution gave it away – a fault later repeated by Wan-Bissaka, moving Harry Maguire, the captain, to inform his side in colourful diction to “tidy up”. Of this, Solskjær said: “They all needed it. Either digging out or calming down. Maybe it was more calming down because the attitude was there.” This had become a contest of home attack versus visiting defence. Greenwood’s footwork split the latter and a menacing cross deserved a finish from a teammate that was absent as Dawson and Fabianski cleaned up. Next, Rashford flipped a pass behind Dawson that put Shaw in close to goal on the byline. Again West Ham escaped, but here was further encouragement that banked resistance could be broken down. Greenwood is impossible to handle when racing in as he did after being fed by Bruno Fernandes. The centre-forward’s twist-then-shot was heading for Fabianski’s right-hand corner before the goalkeeper tipped it on to the post. Greenwood was distraught, yet West Ham were wobbling. Lacking was a killer touch, as when Daniel James fired in a ball at the second half’s opening that had no teammate to turn home. Copious possession means nothing if it fails to yield goals and there is also the danger of being sucker-punched on the counterattack, though West Ham’s lack of ambition tempered this. Given their position, Moyes may have plotted for a draw but if so he soon required a rethink. After Greenwood’s cross was left by Dawson it was stabbed out by Vladimir Coufal. Now, Dawson paid for the error: Fernandes pinged in the corner from the left, Scott McTominay rose, as did the centre-back, who was closely attended by Maguire: Dawson’s header was a classic own goal, coming as he tried to clear but contriving only to beat Fabianski with unwanted ease. West Ham’s riposte came via a penalty shout when Tomas Soucek was challenged by Maguire, but Atkinson awarded a goal-kick. At the other end Fernandes’s 20-yard effort was kept out by a strong Fabianski palm. West Ham probed but Greenwood went close to a second when he hit Fabianski’s right post. “Mason deserved a goal - he was excellent tonight, ” said Solskjær, who will have reinforcements for Milan. “It is very likely that Edinson [Cavani] and Anthony [Martial] are fit, Donny [van de Beek] hopefully as well. Paul [Pogba] even might make the trip and David [de Gea] is back from isolation.” Solskjær was asked if he’s in discussions regarding a new contract. “My thoughts are on doing my job as well as I can,” he said. Moyes said: “[I’m] disappointed that we have lost but parts of the game we played OK and other parts we didn’t.”