The 10th round of the Spanish league programme finished on Monday with a 2-0 home defeat of Valencia to Sevilla, on second-half goals from Alvaro Negredo and Alejandro Alfaro.
Valencia played for 65 minutes with 10 men, because Turkish midfielder Mehmet Topal was sent off harshly, midway through the first half, for a foul on Martin Caceres.
Sevilla are now level with Valencia in fifth place, both with 17 points from 10 matches. They are one point below fourth-place Espanyol and one ahead of surprise package Real Sociedad, who are seventh.
Valencia have picked up just one point in their last four matches and never seemed capable of ending their bad run once Topal had been given a direct red card.
The visitors suffered another stroke of bad luck just before half- time when veteran goalkeeper Cesar limped off injured.
The first goal came 10 minutes into the second half. Vicente Guaita, Cesar's replacement, failed to hold a shot from Caceres, and Negredo followed up to make it 1-0 with is trusty left foot.
Thirteen minutes from time, Sevilla right-back Mouhamadou Dabo centred perfectly for Alfaro to head in the second goal from close range.
Sevilla strikers Luis Fabiano and Diego Capel hit the woodwork toward the end, with the overworked Valencia defence gasping for breath.
Negredo said that "the sending-off (of Topal) was important, but we had to work hard for this win. They are a difficult team to play against, even with a man less on the field."