Led by Salva Sevilla's brace, Real Betis dealt Valencia their third straight loss, a 3-1 defeat in Seville.
Valencia's sloppy passing helped Jorge Molina put Betis ahead in the ninth, and the striker threaded a through ball for a charging Sevilla to fire by goalkeeper Diego Alves in the 22nd.
Alves made the first of several saves to deny Molina in the 32nd, but he failed to stop Sevilla from poking the ball between his legs in the 35th for his second goal of the night.
Valencia defender Ricardo Costa pulled one back with a header from a free kick in the 67th, but his team never threatened after.
Morocco striker Mounir El Hamdaoui scored a hat trick and set up another goal in his first start for Malaga on Sunday in a 5-0 thrashing of Rayo Vallecano.
El Hamdaoui joined Malaga at the close of the transfer window, and with one start equaled his goal scoring tally from last season with Fiorentina.
El Hamdaoui volleyed in Vitorino Antunes' outswinging cross to open the scoring in the 31st and nine minutes later the former Ajax generously squared the ball for Francisco Portillo to make it 2-0.
Malaga's Eliseu Pereira put the result beyond doubt three minutes after half-time with an unstoppable shot inside the far post.
El Hamdaoui finished off a great team buildup in the 62nd with the ball passing through the legs of Portillo, Pedro Morales and Jesus Gamez before he pushed it home.
He then used a hard left-footed strike to drive his third goal between the goalkeeper and the post to cap Malaga's first win in four rounds this season under new boss Bernd Schuster. Espanyol stayed unbeaten by winning 1-0 at 10-man Granada thanks to Manuel Lanzarote's 76th-minute free-kick.
Lanzarote gently curled the ball off the post and into the net from a free-kick inside Granada's area awarded to Espanyol after the referee ruled that goalkeeper Roberto Fernandez had handled a back pass from a defender.
Televised replays showed that the ball appeared to take a deflection off an Espanyol player, suggesting the free-kick should not have been given.
Granada's tempers boiled over in the 82nd when substitute Odion Ighalo received back-to-back bookings, both for protesting to the referee.
Getafe striker Nicolas "Miku" Ladislao netted a double in a 2-1 win over last-place Osasuna.
Miku's performance helped ruin the debut of Osasuna's new manager Javi Gracia, who replaced the fired Jose Mendilibar two weeks ago.
Osasuna started brightly on the road in Madrid with Roberto Torres scoring in the 24th, but Miku headed in a corner kick that had sailed over goalkeeper Andres Fernandez to level in the 35th.
After his acrobatic kick had sent the ball off the woodwork, Miku used a nifty touch to slip the ball under a defender before placing his second goal just inside the post in the 52nd, sending Getafe on its way to their first win of the season.