A howler from goalkeeper Sergio Rico cost Sevilla the chance to close to within two points of La Liga leaders Barcelona in a 1-1 draw at Alaves on Monday.
Wissam Ben Yedder drilled home into the far corner to put the visitors in front with the only clear chance of the first-half.
However, Sevilla had to withstand wave upon wave of Alaves attack after the break and finally crumbled 15 minutes from time.
Rico fumbled Oscar Romero's cross from the right and Aleksandar Katai gratefully tapped into an empty net from close range.
Sevilla captain Vicente Iborra had a chance to immediately restore the lead, but blasted over from the edge of the area.
However, Rico redeemed himself with two great saves late on from Katai's free-kick and Deyverson when one-on-one with the Brazilian striker to at least salvage a point.
Sevilla remain third, but are now four points adrift of Barca and three off second-placed Real Madrid, who also have a game in hand over their title rivals.