Samu and Adrian Lopez got the goals for the visitors to take them six points clear of fifth-placed Athletic Bilbao with just two games remaining, while their superior head-to-head record over their Basque rivals means that they cannot be caught in fourth.
Fresh from their last-gasp first-leg victory over Liverpool in the semi-finals of the Europa League on Thursday, the Yellow Submarine were ahead after just 14 minutes this evening when Roberto Soldado found Samu, who controlled the ball before picking out the bottom corner from the edge of the box.
Soldado has been a creative force all season for Marcelino's men, and the former Tottenham Hotspur striker picked up yet another assist shortly after the half-hour mark as the visitors doubled their lead.
It was Adrian, who also scored the late winner against Liverpool at El Madrigal in midweek, who did the bulk of the work, though, as he dribbled his way into the box before lifting his finish over the keeper.
Soldado came close to getting his own name on the scoresheet with five minutes remaining of the first half when he produced a snap snot from the edge of the area, but the ball whistled narrowly past the upright.
Valencia, who went into the match having scored at least twice in each of their last four games, were struggling to create anything going forward and rarely threatened to haul themselves back into the contest.
Indeed, it was Villarreal who came closest to adding the game's third goal when Adrian saw his deflected effort come back off the post with a little over 20 minutes of the match remaining.
There were no further goals at either end, however, as Villarreal comfortably saw the game out to end a three-match winless streak in the league ahead of their trip to Anfield on Thursday.
Valencia, meanwhile, see their four-game unbeaten streak come to an end and remain eighth in La Liga.