Needing a response after back-to-back league defeats, Celta started on the front foot, coming close through Marcos Alonso and Fer López in the opening stages.
With momentum already on their side, the hosts were handed a further boost when Eric Bailly was shown a straight red card for a mistimed challenge on Alfonso González, who was bearing down on goal.
Villarreal survived just eight minutes with their numerical disadvantage, finally falling behind on the brink of half time as Fran Beltrán’s low ball across goal found the unmarked López for his second goal of the season.
Os Celestes remained in the ascendancy after the restart, and with 53 minutes on the clock, they doubled their lead in somewhat chaotic fashion.
Introduced at half time, Ilaix Moriba struck the post when the ball broke to him on the edge of the area, leading to a phase of pinball before Borja Iglesias took charge by guiding home the game’s second goal.
With an hour gone, the visitors had struggled to impose themselves on the contest, and the points were almost wrapped up when another substitute, veteran Iago Aspas, nearly capitalised on a defensive error with a first-time shot that had Luiz Júnior backpedalling.
A dominant display looked as if it would be wrapped up by Moriba’s rifled long-range effort, but after that was tipped over, the substitute had his say, going down under Pape Gueye’s challenge to hand his side a penalty.
Aspas assumed responsibility, converting from the spot to cap off the scoring on an excellent evening’s work for the hosts.
The result marks just a third away H2H defeat in 14 encounters for Villarreal, who remain in the fifth and final UEFA Champions League spot, just one point above Real Betis Balompié with six games to play.
As for Celta, more home joy means they have now taken 33 points from a possible 46 at Estadio de Balaídos this term (W10, D3, L4), leaving them seventh in the table and with European qualification looking like a genuine possibility.
Flashscore Man of the Match: Óscar Mingueza (RC Celta de Vigo)