Sporting defeated Rayo Vallecano 2-1 at home to move onto 31 points, five shy of safety with four games remaining in the Spanish top flight.
Gaston Sangoy put Sporting in front and after Mikel Labaka levelled for Rayo, the home side found a winner through Mate Bilic.
Rayo were reduced to nine men when Labaka and Jose Manuel Casado were dismissed.
Zaragoza stay level with Sporting on 31 points after suffering a 1-0 loss away at Real Mallorca.
Victor scored the only goal of the game after 33 minutes at Iberostar Estadi.
The game at the Sanchez Pizjuan had been moved back to 22:30 local time (21:30 UK time) because of the 'Clasico' between Barcelona and Real Madrid that kicked off two-and-a-half hours earlier.
"The match has begun but it has now been suspended because of the throwing of tennis balls," Levante wrote on their Twitter feed. "It's a form of protest over the 'Clasico'."
The protest mirrored a similar incident in late 2010 by fans of FC Basel, who showered the pitch with tennis balls during a game after the kickoff time was changed to avoid a clash with a local tennis tournament.
When play resumed, Alvaro Negredo gave Sevilla a 21st-minute lead, Arouna Kone levelled for the visitors seven minutes later and Negredo missed a late penalty as the match ended 1-1.
Levante stay fifth on 49 points, two behind Malaga who play at Osasuna on Monday. Sevilla are sixth on 46 points. Fourth place offers a Champions League playoff spot.