With 117 minutes gone and the score 1-1, Harry Maguire leapt for a header in the Norwich City box and was bumped to the ground. Manchester United’s centre back had barely got to his feet before he was down again, writhing and stretching to poke a loose ball across the goalline after Paul Pogba had crossed back into a crush of exhausted human flesh. Norwich, down to 10 men, had no time to restart their engines. As the final whistle blew both sets of players sank to the Carrow Road turf. A round of weary hugs commemorated the fact United had won this FA Cup quarter-final 2-1, and deservedly so on the balance of a slow-burn muddle of a game. It was a struggle at times, and not just for both sets of players. Over the 120 minutes United had 36 shots at goal, 28 of them off target, many brilliantly saved by Tim Krul. They made six substitutions, a first in English football. For the final 25 minutes they had four strikers on the pitch, plus the Pogba-Fernandes creative axis. Still, though, this felt like football played through a mist. In the first half it took 43 minutes for either team to muster something close to a shot on target, as Todd Cantwell produced a neat little swivel to feed Lukas Rupp, whose shot was well blocked by Maguire. The lassitude was understandable. Name something stranger than a Premier League game in an empty stadium in late June. How about an FA Cup quarter-final in an empty stadium in late June? At kick-off Carrow Road had seemed a gentle place in the evening sunshine, with a sense of somnolence around the empty seats that seemed to transmit itself to both sets of players. There were other factors, too. United made eight changes: sensible given the flood of games, but a note of disappointment for those intrigued by the growing fluency of United’s attacking play. For Norwich, Cantwell and Teemu Pukki returned, a pleasant surprise for the dear old FA Cup, restored here to the status of A-list competition. Jesse Lingard and Juan Mata combined nicely early on. Jamal Lewis began with a sense of long-striding adventure down the Norwich right. But steadily the red shirts settled into a pattern of stodgy lateral passing. Fred saw a lot of the ball, although this didn’t always feel like the kind of relationship the ball’s closest friends would necessarily encourage. “Keep moving it,” a voice shouted from the touchline as Maguire doodled around in midfield. It was left to the drinks break to provide a rare show of animation as Daniel Farke, dressed in a shiny black plastic raincoat, pounded his fist and demanded greater urgency. Soon afterwards Kenny McLean robbed Juan Mata, rumbled forward and smashed a shot high on to the plastic sheets behind the goal. It was that kind of first half. For long periods nothing happened energetically. In between, nothing happened more slowly. The break seemed to come as a relief to both teams. And six minutes after half time something did finally happen, as United opened the scoring. Luke Shaw made the incision, driving down the right and crossing at chest-height. Mata seemed to produce a clever touch over two Norwich defenders, although replays showed the ball came off Max Aarons. Odion Ighalo had been left unmarked. He flicked it into the net past Tim Krul with the outside of his foot, an easy, expert finish. This was Ighalo’s fifth United goal, all of them in cup competitions. He has been a shrewd hire, a smart, experienced player to do exactly this kind of job. The goal brought a surge of energy from Norwich, who should have scored just after the hour. Ben Godfrey somehow cleared the ball off the United line with his shoulder after a low free-kick from Emi Buendía was glanced on by Bruno Fernandes. Steadily Norwich began to pass and move with some fluency and on 75 minutes Cantwell produced a fine equaliser. Onel Hernández laid the ball inside and Cantwell’s shot zinged into the bottom corner. There was time for a final twist. Brandon Williams, on as a sub, produced a fine goal-saving tackle on Hernández. And on 88 minutes Timm Klose was faced with a similar moment of danger but could only conjure a ludicrous bear hug on Ighalo as he span away. Ighalo would have been in on goal. Klose was rightly sent off. The free-kick from Fernandes was scuffed low into the wall. By now United had Pogba and Rashford on, along with Fernandes and Greenwood, an ominous prospect for an undermanned home team. At the death Krul made a miraculous double save, first from Pogba then Greenwood. United duly dominated extra time but without creating any really clear chances – right up until Maguire’s act of euthanasia at the death. “It was a difficult game and we made hard work of it,” the match-winner told the BBC. “We weren’t at our best and sometimes in cup games that happens. You’ve got to find a way to go on and get the victory and get through to the next round and we’ve managed it in the end.”