Athletic Bilbao beat Mirandes 2-1 in the first leg of their Copa del Rey semifinal on Tuesday, yet conceded a stoppage-time goal to give the third-tier club some hope ahead of the second leg next week.

Mirandes' partisan crowd of 8,000 spectators at Anduva stadium were silenced after 18 minutes when Fernando Llorente read Oscar de Marcos' run to head in the ensuing short cross at the far post for the opener.

With Spain coach Vicente del Bosque in the stands, Llorente continued his hot scoring run of late with an individual effort in the 27th. The Spain striker cut in from the left and dummied a shot, continuing his run before sliding the ball beyond goalkeeper Nauzet Cecilio.

But the hosts cut the deficit in the first minute of stoppage time when Ander Lambarri gathered a long ball inside the area and turned to beat goalkeeper Gorka Iraizoz.

''We're going to have to play the match of our lives,'' Mirandes coach Carlos Pouso said of next Tuesday's return at the San Mames stadium.

Mirandes is only the third team from below the second division to progress this far, after Figueres in 2002 and Deportivo Logrono in 1931.

''The truth is it was a tough game,'' said Llorente, who has eight goals in his past six games. ''We started well but that late goal is a shame because we'd played a good game until then.''

An extra 1,700 seats were added at Anduva after Mirandes eliminated topflight clubs Villarreal, Racing Santander and Espanyol.

Pablo Infante, the competition's leading scorer who works as a banker by day, led the hosts' early charge.

Bilbao's Iker Muniain looked to have scored Athletic's third in the 63rd but was wrongly judged to be offside.

Mirandes dominated the chances afterward, with Iraizoz tipping Haritz Mujika's volley over the bar then palming Cadena's volleyed shot to deflect onto the crossbar in the 75th.

Jose Angel Jurado volleyed wide before Lambarri gathered Caneda's long ball in the left side of the area and turning to fire under Iraizoz.

''It was clearly a game of two halves,'' Pouso said. ''We weren't able to do more. You couldn't help but notice our opponents were from the first (division).''