Teenage star Lamine Yamal struck twice as La Liga leaders Barcelona thrashed Girona 4-1.

Hansi Flick's side have now won all five of their opening matches and avenged two humiliating Catalan derby defeats by Girona last season with an emphatic victory at Montilivi.

Yamal's first-half double sent Barcelona on their way with Dani Olmo and Pedri Gonzalez adding further goals after the break.

Cristhian Stuani pulled one back for the hosts, last season's surprise package who finished third in only their fourth season in the top flight.

Girona lost several key players in the summer with coach Michel Sanchez forced to rebuild.

Barcelona have new momentum under former Bayern Munich and Germany coach Flick and produced their best performance of his reign to date.

"I think you can see the confidence we have, and when we have the ball, we have the quality to play and to create chances," Flick told reporters.

"I think today we had a lot of chances to score one or two goals more, but in the end I'm very happy with the performance of the team."

Yamal and striker Robert Lewandowski came close in the opening exchanges before the teenage star, who led Spain to Euro 2024 victory in the summer, broke the deadlock.

The winger picked the pocket of David Lopez as he tried to bring the ball out of defence, before finishing with aplomb past Paulo Gazzaniga after 30 minutes.

"We started very concentrated, very focussed, we pressed them -- we know when we give them the space they need for combinations we get in trouble," said Flick.

"You saw the first goal, it was unbelievably good (pressing) from Lamine."

Yamal grabbed his second before the break with a fine guided finish from the edge of the box after a free-kick was cleared into his path.

Bryan Gil fired straight at Marc-Andre ter Stegen from close range at the other end, before Girona were awarded a penalty when Inigo Martinez handled the ball.

However after a VAR referral the referee annulled his decision, seeing that it had bounced on to Martinez's arm off team-mate Alejandro Balde.

Olmo expanded Barcelona's lead early in the second half with a sublime finish from a tight angle, leaving the new arrival from RB Leipzig on three goals from three La Liga matches.

Gazzaniga denied Lewandowski as he ran through on goal and tried to finish with a dink, as Barcelona maintained control.

Their fourth came through Pedri when midfielder Marc Casado cleverly played him through and the Canary Islander took his time to sidestep Gazzaniga and finish.

"We had to start (the season) well, other years we didn't start it as we would have liked, above all the coach told us that," Pedri told Movistar.

"(He told us) that from the first game we should push, that the league is won above all in these first games if you keep building the distance up, let's continue in the same way."

- 'Turn the page' -

Former Espanyol striker Stuani finished from close range with 10 minutes remaining to give Girona a consolation, before Barcelona substitute Ferran Torres was sent off for a high tackle on Yaser Asprilla.

They were the only blots on Barcelona's otherwise pristine copybook as they maintained their 100 percent record at the start of the campaign.

On Saturday champions Real Madrid earned a 2-0 win at Real Sociedad to move second, four points behind Flick's side.

Girona are seventh after the defeat, with their next match a Champions League debut away at Paris Saint-Germain.

"It feels bad, it was a tough defeat today, for how we were preparing for the game and the excitement of facing Barca again at home," Stuani told Movistar.

"We have to try and forget about it as quickly as possible, this week we have a very special game, we have to face that with as much excitement as possible because for us it's an historic match.

"We have to turn the page on today and try to compete in the best way (we can)."