Felipe Caicedo came off the bench to score a 90th-minute winner to hand Espanyol a 1-0 Primera Division victory over Celta Vigo.
Caicedo scored two late goals as Espanyol overcame Valencia to reach the Copa del Rey quarter-finals on Tuesday, and the Ecuador striker's close-range finish earned his side all three points at the Power8 Stadium on Saturday.
The victory for Sergio's side saw them leapfrog Celta Vigo into ninth place, with Eduardo Berizzo's side slumping to 11th after they extended their La Liga winless run to nine matches.
Espanyol started brightly and had the first chance of the game, but midfielder Jose Canas could only shoot wide of Celta goalkeeper Sergio's left-hand post with a speculative 25-yard effort.
Sergio Garcia tried his luck from long range a few minutes later but, like his team-mate, he too could not find the target.
Lucas Vazquez should have put Espanyol ahead shortly after the half-hour mark when he found himself in space just inside the penalty area, but he could only blaze Salva Sevilla's corner over the bar.
Celta were offering very little in attack and did not register a shot at goal in the first half, but finally did so five minutes after the restart but Kiko Casilla saved Joaquin Larrivey's 20-yard strike comfortably.
Espanyol soon exerted their dominance once again and Christian Stuani really should have done better when he was picked out by a pinpoint Sevilla free-kick, but the Uruguay international striker could only head over the bar.
Espanyol pair Anaitz Arbilla and Canas went into the book shortly after and they were soon joined by Celta centre-back Andreu Fontas, who was cautioned for unsporting behaviour.
The hosts were almost made to pay when Larrivey found himself with space to shoot inside the six-yard area but Casilla was quick to narrow the angle and smother the shot.
Espanyol manager Sergio blinked first and replaced Sevilla with Paco Montanes with 20 minutes to go, before Stuani made way for Caicedo seven minutes later.
Celta boss Eduardo Berizzo responded by sending Sergi Gomez on for Michael Krohn-Dehli, but it was Espanyol who would have the last laugh with Caicedo following up his match-winning midweek brace with a winner with 22 seconds of normal time remaining.
Caicedo gave Sergio no chance when he slotted home from six yards out from the right-hand side of the penalty area and Celta could not snatch an equaliser in the three subsequent minutes of added time.