Valencia tore Real Madrid apart 3-0 on Saturday to give Barcelona the chance to wrap up the Primera Liga title as early as Sunday's game against Villarreal.
Real's 6-2 defeat by Barca last weekend looked to have taken a heavy toll as Valencia scored twice in three first-half minutes through Juan Mata and David Silva, with Ruben Baraja added a stunning third after the break.
Real remain second with 78 points and three games left, seven points short of Champions League finalists Barca, who have four to play.
The first of those games is at home to Villarreal on Sunday, when a victory would be enough to see them over the line.
Earlier, third-placed Sevilla were inspired to a 3-1 home win over Real Mallorca by Luis Fabiano.
That moved them on to 63 points and kept them four ahead of chasing Valencia in the race for the Champions League qualification places.
Real keeper Iker Casillas pulled off a magnificent early save at the Mestalla with his team firmly on the back foot, but he was beaten in the 29th minute when Valencia's attacking trio of Silva, Mata and David Villa combined for a slick opener.
Mata put away Villa's lay-off, and soon after Silva cut in off the left flank and fired in from distance only for Casillas to weakly push the ball inside his near post.
The visitors were helpless in the face of Valencia's quick, incisive attacks and after 68 minutes midfielder Baraja rubbed salt in the wound with a spectacular volley from outside the area.
At the Sanchez Pizjuan, Aritz Aduriz had given Mallorca an early lead before Sevilla's Brazil striker Fabiano was brought down for a penalty as he surged into the area.
Frederic Kanoute's dummy sent the keeper the wrong way from the spot, before Fabiano spun away from his marker in midfield and burst away from three defenders to net Sevilla's second on the hour mark.
Jesus Navas jinked in off the right wing to seal the win with a fierce drive into the far top corner.
Athletic Bilbao secured their top-flight future with a 1-0 home win over Real Betis.
Athletic coach Joaquin Caparros's gamble to rest a large number of first-team regulars ahead of Wednesday's King's Cup final against Barcelona paid off at San Mames.
Ion Velez sidefooted home a well-worked move after 29 minutes and Athletic's reserve goalkeeper Armando was alert to keep out Betis, who remain just three points above the drop zone.
