Athletic had two clear chances to take the lead and there were controversial refereeing decisions as the Red Devils won 3-0
Athletic Club were beaten 3-0 in the first leg of the Europa League semi-finals at San Mames in a painful, controversial and contentious defeat.
We still have the return leg at Old Trafford, the Theatre of Dreams, where the Lions will be looking for a complicated but not impossible victory.
With a packed San Mamés, Athletic came out determined to find a way back into the game.
And after Alejandro Garnacho had a goal ruled out for offside, Athletic had three chances, two of them very clear, to make it 1-0. First up, Andre Onana saved Alex Berenguer's left-footed shot and Iñaki Williams sent a header just over the bar.
The third was no less clear-cut. Mikel Jauregizar found Iñaki Williams down the flank and the winger's cutback to Berenguer was blocked on the line by Victor Lindelof.
However, United made it 0-1 with their first proper chance - Harry Maguire's cross was flicked on in the box and Casemiro headed in at the far post. It was the half-hour mark and a real dagger to the side.
The Lions lost their nerve and were severly punished in the next action. Garnacho touched the ball with his hand before falling to the ground in a duel with Yuri and his subsequent cross towards Rasmus Hojlund, who won a penalty after a brief tussle with Dani Vivian. VAR took an age to come to a conclusion.
The punishment was made worse when the referee sent Vivian off, even though it didn't seem to be a goalscoring chance for the Danish striker.
Bruno Fernandes showed no mercy from the spot and the Portuguese midfielder then made it 3-0 after going through one-on-one with Julen Agirrezabala.
Ernesto Valverde made a double change bringing on Aitor Paredes and Andoni Gorosabel, who replaced the injured Oscar de Marcos, on the night the captain replaced Markel Susaeta as the Lion with most European appearances.
Athletic were outraged by Harry Maguire's subsequent challenge on Maroan, which was not even flagged for a foul when it could have been a sending-off.
With all the respect that this club maintains publicly and privately towards referees, the mistakes piled up.
The defeat did not get any worse thanks Julen Agirrezabala saves, and Athletic pushed hard for a goal to shorten the gap. Unai Gómez and Alvaro Djaló almost got one too.
