Benat Etxebarria fired home an injury-time free-kick to hand Real Betis a dramatic 2-1 derby victory and deal a potentially fatal blow to Sevilla's hopes of claiming a UEFA Europa League qualifying place.
Etxebarria's low drive dragged Betis level on points with their neighbours on 46 points but leaves the pair four points off sixth-placed Atletico Madrid with two Primera Liga games to go.
The hosts went into the game without a win in three but made a dream start when Alvaro Negredo struck the opener after six minutes following a cross from the left by Piotr Trochowski.
Betis keeper Fabricio saved well from Manu in the 14th minute before the visitors had their first chance two minutes later with Iriney heading wide from 18 yards.
Betis came close in the 28th minute with Alejandro Pozuelo and Etxebarria both coming close before the ball fell to Paulao, whose header from the centre of the box flashed just wide.
The visitors finally drew level two minutes before half-time when Etxebarria curled home the opener from 25 yards.
Both sides had chances early in the second period, Jose Antonio Reyes missing the target for Sevilla and Ruben Castro also firing wide for Betis.
Fabricio saved efforts from Negredo and Jesus Navas while Negredo saw another opportunity sail over the bar 12 minutes from time.
Castro appeared to have missed the visitors' last chance when he fired wide in the 89th minute, but moments later the same player was fouled by Federico Fazio and Etxebarria fired the free-kick home from 18 yards.