Villarreal sealed their place in next season's Champions League play-off by winning 2-0 at local rivals Valencia thanks to first half goals from Samu Garcia and Adrian Lopez.
Athletic Bilbao's 3-2 win over Celta Vigo earlier on Sunday meant Marcelino's side would seal their return to Europe's elite competition for the first time in five years by beating Valencia, and although the hosts made the stronger start, Garcia put Villarreal on their way to victory in the 14th minute.
Adrian then built on his last-gasp winner against Liverpool in Thursday's Europa League semi-final first leg by coolly slotting in the second goal in the 33rd minute.
Villarreal stay fourth in the Primera Division table, six points clear of Athletic and with a superior head-to-head record than the Basques, and seven above Celta.
Aderlan Santos and Dani Parejo both had early chances to score for Valencia but failed to hit the target, and Villarreal went ahead with their first chance of the game, Garcia appearing between two defenders to hook Roberto Soldado's cross past Diego Alves with his right foot.
Former Sevilla striker Alvaro Negredo was denied a goal against his old club by a save from Alphonse Areola, and at the other end ex-Valencia favourite Soldado narrowly missed the target.
The visitors got their second when Adrian took advantage of a high Valencia defensive line to latch onto a long ball and race into the area before calmly chipping it over Alves.
Adrian nearly forced a third goal after the break when his cross diverted off Guilherme Siqueira and off the post, and Valencia had to play the final 10 minutes a man down after Denis Cheryshev was forced off injured after Pako Ayesteran had used his three substitutions.
ends