Athletic Bilbao dominated Granada in the Copa del Rey semi-final first leg but were only able to earn a 1-0 win on Wednesday.
The Basques, who knocked out Barcelona in the quarter-finals, impressed at a raucous San Mames and had two goals disallowed for offside.
Inaki Williams had a low shot tipped round the post by Rui Silva and Raul Garcia was narrowly off target, before Iker Muniain put Athletic ahead after 42 minutes.
Yeray Alvarez and Ander Capa’s strikes were ruled out as Athletic were unable to build on their lead before the second leg in Andalusia on March 5. (Reuters/NAN)