The Spain international struck twice in the first half and, after Pape Gueye pulled one back for the visitors at Camp Nou, stroked in a third for Hansi Flick's side.

Robert Lewandowski rounded off Barca's triumph with a late tap-in as they extend their lead on Real Madrid, who host Getafe on Monday, and third-place Villarreal who now trail the champions by 13 points.

Yamal, who seems to have fully recovered from a groin issue which bothered him for several weeks earlier in the campaign as he struggled to hit top form, was at his effervescent best.

"It was a mix of everything. I wasn't feeling good about myself, plus the (groin issue) as well, I wasn't playing happy, and I think it showed," Yamal told Movistar.

"For about a week or so now I've been feeling much better. It was that desire to smile while I was playing that I hadn't felt for a long time, and now I'm happy. I'm happy playing and really content."

The winger became the youngest player to score a hat-trick in La Liga in the 21st century at 18 years and 230 days old.

Yamal has now equalled his tally of 18 goals last season across all competitions, becoming the team's top goalscorer and raising the one area of his game which called for improvement.

"I think that (I've improved over time), what happens is that people want me at 16 years old to score 100 goals and I'd like that too, but it's very hard," continued Yamal, with the match ball tucked under his arm.

"So (I'm improving) bit by bit, but I'm very happy, when it's a goal, or two goals, to help the team."

Barcelona might have taken the lead through Jules Kounde early on but the French defender screwed a shot across the face of goal when well placed.

Yamal tested Villarreal goalkeeper Luiz Junior from distance, offering a brief glimpse of what was soon to follow.

Barca took the lead when Fermin Lopez won the ball high up the pitch and fed Yamal, who curled home after 28 minutes.

Yamal's second followed nine minutes later, a stunning individual goal after he drove in from the right.

The teenager left Sergi Cardona and Alberto Moleiro for dead and then whipped a strike into the far top corner.

Luiz Junior saved Raphinha's free-kick as Barca sought a third before the interval. Kounde flicked home but was offside and Yamal might have completed his hat-trick but fired over.

- The Yamal show -

Dani Olmo wasted a good chance early in the second half and soon paid the price as Villarreal pulled one back.

Gueye turned home from close range after a scramble in the box as Barca failed to clear a corner.

The Yellow Submarine nearly had a second when Joan Garcia came flying out of his goal to try and beat Ayoze Perez to a ball in behind Barca's defence.

The goalkeeper did not win it cleanly and, after Perez recovered possession, the Canary Islander fired just wide with Garcia stranded in no man's land.

Yamal bent another shot agonisingly wide from the edge of the box as he chased his first ever treble, which eventually came after substitute Pedri played him in with an inch-perfect pass.

The teenager beat Luiz Junior with a clinical finish and was given an ovation when Flick brought him off shortly afterwards.

Lewandowski netted Barca's fourth after good work from Pedri and Kounde, who had one of his best games of the season.

Scoring four goals -- at least -- is what Barca need to do on Wednesday, as they host Atletico Madrid in the Copa del Rey semi-final second leg, aiming to overcome a 4-0 deficit.