Barcelona came from behind for the second week running to keep their title hopes alive.
Cani's opener just before halftime and Trigueros's header had Barcelona staring down the barrel.
But, own goals from Gabriel and Musacchio and a late winner from Lionel Messi handed Barcelona a lifeline in the title race.
It was a emotionally charged evening in Villarreal as both sides honoured Tito Vilanova, who sadly lost his battle with cancer on Friday aged 45.
In an act of class Villarreal wore t-shirts bearing the words 'Forever Tito'. While the emotion from the Barcelona players was evident with Sergio Busquets shedding a tear prior to kick-off.
The first-half went almost without incident until late in the half when Villarreal turned on the heat.
First Marc Bartra was forced to clear off the line by Javier Aquino, then Barcelona found themselves behind when Cani capitalised on through ball from Jonathan Pereira.
Ten minutes into the second half Barcelona's title hopes appeared to be in tatters as Trigueros emphatically headed home to give Villarreal a 2-0 lead.
But Villarreal shot themselves in the foot as Gabriel turned in a Dani Alves shot and Musacchio headed into his own net to give Barcelona hope.
Messi completed the turnaround with seven minutes remaining as he impressively finished a Cesc Fabregas knockdown.
With the win Barcelona remain four points behind league-leaders Atletico Madrid with three games left.