BILBAO, Spain — Ruben Amorim warned his Manchester United players that they have not yet booked their place in the Europa League final despite a dominant 3-0 win over Athletic Club in their semifinal first leg on Thursday.

United are on the brink of setting up a European final against Premier League rivals Tottenham Hotspur — 3-1 winners over Bodo/Glimt in the other semifinal first leg — thanks to three goals in 15 minutes at the end of the first half at San Mames.

It came after Athletic Club, who had Dani Vivian sent off in the first half, had created a number of chances in the opening 20 minutes before the game was turned on its head.

“I think they have to think about the second leg,” said Amorim,

“And they have to think more about the first 20 minutes than the rest of the game because the game is going to be really tough.

“There is no away goals so anything can change and that is my message to the players, and we have to think now about Brentford [on Sunday] and then the second leg”

After Athletic Club had failed to make the most of their quick start, Casemiro scored United’s opener with a back post header.

Vivian was sent off following a VAR review for a pull on Rasmus Højlund and Bruno Fernandes converted the penalty. Fernandes scored again just before the break and it could have been even better when Noussair Mazraoui hit the bar.

“I think it is the best result because nobody expected this result,” said Amorim.

“But, again, I think you saw two games today — the first 25 minutes and then after the goal, and also with the sending off the game changed.

“That was a good thing, also a good thing in the second half was we tried to be cautious.

“We create chances but the most important thing is that the opponent didn’t get many shots to our goal and that was really important.”