Bruno Fernandes struck twice as Manchester United put one foot in the Europa League final with a clinical away performance to beat 10-man Athletic Bilbao 3-0 on Thursday.

The fervent home fans were enraged when Athletic defender Daniel Vivian was sent off for pulling back Rasmus Hojlund and Fernandes slotted home the resulting penalty, after Casemiro had opened the scoring against the run of play in the semi-final first leg.

Fernandes rolled in a third before half-time as Ruben Amorim's side moved a step closer to the final, to be held at Athletic's San Mames stadium.

The hosts have been dreaming of winning a first European trophy on their own soil but their hopes were demolished by United's professional display in the north of Spain -- and Athletic's supporters argued, the refereeing.

"I think it's the best result (of my tenure) because nobody expected this result -- but you saw two games today," Amorim told reporters.

"The first 25 mins, then (another one) after the goal and the sending-off."

Languishing in 14th in the Premier League, Champions League qualification for United is only possible with a Europa League triumph, as is access to the £100 million ($133 million) honeypot it entails.

Despite regularly crumbling under pressure this season, the Red Devils -- who produced a stunning comeback against Lyon in the quarter-finals -- first survived and then thrived in a hostile environment.