Argentine striker Lautaro Acosta scored an injury-time winner to give Sevilla a 2-1 victory at home to Athletic Bilbao in their King's Cup semi-final first leg on Wednesday.
Fernando Llorente had headed the visitors in front just before halftime, but Sevilla stormed back after the break.
Aldo Duscher levelled though it looked as though Athletic would hang on for the draw after Frederic Kanoute's 84th-minute penalty was saved, before substitute Acosta scrambled the winner in injury time.
The match at the Sanchez Pizjuan was 15 minutes late in starting after a cloudburst soaked the pitch, and the remaining surface water made it difficult for both sides to pass the ball.
The first half was played at a hectic pace and the home side came close to breaking the deadlock when Ndri Romaric headed against the crossbar at a corner.
Andres Palop tipped a fizzing Llorente volley over the bar four minutes before halftime but he was caught out at the ensuing corner.
The Sevilla keeper came for the ball but the Spain striker beat him to it, flicking his header inside the far post.
The 2007 Cup winners levelled after a frantic goalmouth scramble in the 61st minute when Argentine midfielder Duscher smashed a loose ball into the roof of the net, and the pressure continued to grow on the visitors goal.
Athletic's Gorka Iraizoz pulled off a string of fine saves and even blocked Kanoute's follow up one-handed after the Mali striker's penalty hit the post six minutes from time.
But Sevilla coach Manolo Jimenez gained the upper hand over his former colleague, Athletic boss Joaquin Caparros, when Acosta finally beat Iraizoz with a low drive.
The second leg at San Mames is scheduled for the first week in March.
On Thursday, the second semi-final first leg pits runaway Primera Liga leaders Barcelona aginst bottom club Real Mallorca.
