Atletico set up Cup semi-final with Real Madrid

Atletico Madrid's midfielder Raul Garcia (R) celebrates a goal with teammates at the San Mames stadium in Bilbao on January 29, 2014 - by Rafa Rivas

Aritz Aduriz had powered the hosts into a deserved lead four minutes before half-time and Athletic were only denied a bigger advantage at the break by two outstanding saves from Thibaut Courtois.

However, Atletico regrouped at the break and levelled 10 minutes after the restart when Raul Garcia smashed home Emiliano Insua's cross.

Diego Costa sealed their passage into the last four in the final stages as he slotted home his first goal of 2014 on the counter-attack to inflict Athletic Bilbao's first home defeat of the season and first ever at their San Mames ground which they have used since the start of the campaign.

Atletico will travel to the Santiago Bernabeu, where they beat Real 2-1 in last year's final, for the first leg of the semi-final next week with the return to come at the Vicente Calderon the following week.

Not for the first time this season, though, Atletico had Courtois to thank for digging them out of trouble as the Belgian produced the sort of form that prompted boss Diego Simeone to say last week he wants to keep the Chelsea loanee at the club at any price.

There was nothing Courtois could do to prevent Athletic going ahead as Aduriz got above Diego Godin to head home Mikel Balenziaga's cross from the left.

The Atletico keeper got revenge on Aduriz moments later, though, as he produced a stunning reaction save from close range to parry the striker's header to safety.

Courtois also flew to his left to prevent a Mikel Rico effort doubling Athletic's advantage before half-time.

No doubt buoyed by a roasting from Simeone at half-time, Atletico came out a different side after the break and Iago Herrerin was forced into two excellent saves of his own to deny Costa's header and a sweetly struck volley from Garcia.

However, the visitors continued to push and got the vital away goal when Garcia swept home Insua's cross from the left.

Courtois ensured Atletico saw out another wave of Athletic pressure after the equaliser with two more smart saves from Ander Herrera.

And Costa got a much needed confidence boost with his first goal in eight games four minutes from time as he rounded the helpless Herrerin before rolling the ball into the unguarded net.