Bruno Fernandes scored twice, against a home team reduced to ten men after barely half an hour, and Casemiro started the rout, in a performance that should see United returning to this stadium for the Final - and, perhaps, a meeting with Tottenham - in three weeks. The night - and, surely, the tie and United’s season - pivoted dramatically in the space of 15 first half minutes, although, given the drama throughout their European campaign, perhaps that should not have come as a surprise. While United’s Premier League campaign is well on course to be the worst since the division was formed, Europe has offered a roller coaster ride of emotions for their supporters who have now seen their team unbeaten in all 13 of their Europa League ties. That may yet bring Amorim his first trophy, barely six months into the job, and guarantee United the £100 million-plus that comes from qualifying for the Champions League next season. And whatever had gone before over the campaign, Amorim deserves credit for this result and composed performance, one of their best in Europe for many years. The opening goal on the half-hour, largely against the run of play, featured some astonishing skill on the wing from centre-half Harry Maguire, the inspiration behind the memorable quarter-final win over Lyon last month. He twisted and turned, in a passable impression of team mate Alejandro Garnacho, twice beating his marker Mikel Jauregizar and crossing to Manuel Ugarte who intelligently headed towards the far post. And there was Casemiro to drive an unstoppable and perfectly-placed header past stranded Bilbao keeper Julen Agirrezabala for a goal that stunned the home crowd. Those supporters were still coming to terms with that calamity barely a minute later when Bilbao’s world - or, at least, their Europa League campaign - came crashing down around them. Noussair Mazraoui’s right-wing cross flew through the Bilbao six-yard box where Rasmus Hojlund appeared to have missed a chance to slide in and convert into an empty net. The United striker reacted furiously, however, convinced he had been held back by Dani Vivian, who accused Hojlund of diving in a fiery altercation. Eventually, VAR intervened and, after a lengthy check, Norwegian referee Espen Eskas checked his video screen, trotted back onto the pitch, pointed to the spot and sent off the defender. It was chaos, Bilbao incensed and claiming that Garnacho had handled in the build-up, a point reflected in the fact it was the 37th minute before events calmed sufficiently for Fernandes to step up and plant a perfect penalty into the bottom right corner of the Bilbao goal. The reaction of home players to the incident, and particularly the red card, suggested they might implode. And that is just what they did. Patrick Dorgu was denied by Agirrezabala at the near post and, in first half injury time, Mazraoui thundered a tremendous strike against the Bilbao from the edge of the area although, by that stage, United had claimed their third. It came on the stroke of half-time as Hojlund won a challenge, Ugarte slipped the ball through and Fernandes strode forward before finishing perfectly. Just like the frantic atmosphere inside the San Mames stadium, the game did not disappoint, at least for anyone not of an Athletic persuasion. And, for a moment at least, it looked as though United had made the perfect start, opening the scoring after four minutes through an excellent finish from Garnacho, only for him to be, correctly, judged offside. Duly warned, Bilbao set about the visitors in a manner that suggested they wanted the tie settled before next week’s return in Manchester. The best chance came on 18 minutes and found Victor Lindelof, handed a rare start and shaky in the opening exchanges, making a superb block from Alex Berenguer’s shot. Andre Onana had kept out a low shot from Berenguer and Inaki Williams missed a glorious opening, placing a free header wide from six yards - all misses that would come back to haunt the hosts as United weathered the storm and rallied spectacularly. The second half was an exercise in game management for United, although Casemiro came close to a fourth when his effort was tipped over and the Brazilian headed against the post from the resulting corner. Garnacho and Fernandes might also have plundered goals. The home fans screamed for Maguire to be shown a red, after a tussle with Maroan Sannadi, although VAR showed he had been fouled first, a moment that proved just how much this was United’s night. Athletic Bilbao (4-2-3-1): Agirrezabala 7; De Marcos 5 (Gorosabel 42, 5), Vivian 4, Alvarez 5, Berchiche 5; Jauregizar 5, Ruiz de Galarreta 5 (Prados 46, 5); I Williams 6 (Djalo 87), Berenguer 7 (Paredes 42, 5), N Williams 5 (Gomez 80); Sannadi 6. Substitutes (not used) Boiro, Canales, Guruzeta, Lekue, Nunez, Simon, Vesga. Manchester United (3-4-2-1): Onana 7; Yoro 6, Maguire 7 (de Ligt 65, 5), Lindelof 7; Mazraoui 7 (Shaw 74, 5), Casemiro 9, Ugarte 7 (Mount 65, 5), Dorgu 6 (Diallo 84); Garnacho 7 (Mainoo 84), Fernandes 8; Hojlund 7. Substitutes (not used) Amass, Bayindir, Eriksen, Fredricson, Heaton, Kamason, Mantato. Referee: E Eskas (Norway) 9