But with Noble flying in once too often, Mkhitaryan's quick free-kick released Juan Mata, who was denied by the ankles of the advancing Hart and when the Spaniard returned the ball into the six-yard box, Arthur Masuaku brilliantly thwarted Lukaku.
Lukaku scored a consolation goal as United lost 2-1 to Real Madrid in the UEFA Super Cup in the Macedonian capital Skopje on Tuesday and his team-mates have been impressed by what they have seen in pre-season.
You do not have access to view this Atom..
Maraoune Fellaini replaced Mata for the final quarter-hour, while Martial came on for Rashford and Aaron Cresswell took over from Masuaku. West Ham lose the ball with Obiang and Rashford breaks. Zlatan Ibrahimovic was an excellent role model for the dressing room and a match-winner on his day, but he could slow United's counters down and had a bad habit of missing good chances. Manchester United have a few players out as well, with the knee injuries to Marcos Rojo and James Wilson still keeping them out long term, as well as long waits off the pitch left for Luke Shaw and Ashley Young. The youngster's effort was off target but it was a warning shot.
RCM - Ander Herrera: The 2016/17 Player of the Year will be looking to light up Old Trafford once again this season, and with Matić behind him we could see a bigger contribution towards goals than ever before, on top of his superb influence in the middle of the park.
United and Lukaku's second followed minutes later and was a reminder of the striker's power rather than pace. Then, after being central to much of United's pretty play, Pogba made a decision to go it alone, carrying the ball forward unchallenged before angling a shot past Hart.
Arnautovic served a reminder of West Ham's threat with a header that De Gea was obliged to tip over, but it seemed only to redouble the home side's determination to stretch their lead. There have been plenty of reasons for United's league struggles; this year, however, everyone at the club will at least expect them to challenge for the title for the first time since Sir Alex Ferguson retired. They will not be the only team to leave Old Trafford bruised and well-beaten this season.