Sergio Garcia hit a hat-trick as Espanyol inflicted a heavy 4-1 defeat on 10-man Rayo Vallecano to move up to eighth in the Primera Division table.
The striker's first two goals came from the penalty spot in either half.
A headed goal from Saul Niguez in the 81st minute gave the hosts brief hope of salvaging an equaliser but barely a minute later Garcia hit his third goal, and then Christian Stuani completed the rout.
Paco Jemez's side were forced to play three quarters of the game with 10 men as goalkeeper Ruben Martinez was shown a red card in the 25th minute for bringing down Garica, and despite playing well in patches, were condemned to their 10th defeat of the season, and as a result remain in the relegation zone.
Rayo had beaten fellow strugglers Celta Vigo in their last match, while Espanyol were hoping to make amends for a 3-1 home defeat to Sevilla.
The hosts made the stronger start and did most of the early attacking, although they were unable to create any clear chances, with their best effort a shot from Lass Bangoura inside the area that was blocked by Hector Moreno.
Espanyol were more cautious and waited until 25 minutes had been played before launching their first attack.
Garcia ran between two Rayo defenders before facing down Ruben, who tripped him up before he could get past.
The goalkeeper was given a straight red card, so veteran stopper David Cobeno came off the bench to take his place, with Alberto Bueno sacrificed.
Garcia made no mistake from 12 yards out.
Despite going a man down, Rayo continued to take the initiative, and Roberto Trashorras was denied an equaliser by Espanyol goalkeeper Kiko Casilla, while Lass hit narrowly over the bar just before half-time.
Rayo appeared to have less energy after the break and it was not long before they were two goals behind, again due to a penalty.
This time it was Jhon Cordoba who went into the area, and took a tumble after a challenge from Anaitz Arbilla. Garcia was again on target from 12 yards, scoring his 50th goal in the Primera Division.
The second goal deflated Rayo, and they were unable to muster up much of a response until the last 10 minutes, when Saul gave them hope as he headed in a corner from Trashorras.
But within seconds of the re-start, Espanyol restored their two-goal advantage, Garcia bundling the ball over the line after a long ball up into the box, and two minutes later substitute Stuani piled further misery on Rayo, passing the ball into the net as Espanyol countered.