Ousmane Dembele scored and provided assists for Sergi Roberto, Robert Lewandowski and Ferran Torres as Barcelona cruised past Athletic Club 4-0 in LaLiga on Sunday.

Barcelona remain second in the standings on 28 points, three behind leaders Real Madrid and five clear of third-placed Atletico Madrid.

- Marsden: Camp Nou roars for dazzling Dembele
- Stream on ESPN+: LaLiga, Bundesliga, MLS, more (U.S.)

Athletic Bilbao manager Ernesto Valverde was returning to Camp Nou for the first time after having been sacked by Barcelona in January 2020.

The Basque side had a great start to the season, climbing to third in the standings at one point, but after four consecutive weeks without a win, they sit sixth on 18 points.

After his team got completely outclassed in their 3-1 loss at Real Madrid last week, Barca manager Xavi Hernandez said he was going to shake things up and he kept his word.

On Sunday, he changed from Barca's usual 4-3-3 system to a 4-2-3-1 with Lewandowski as the target man up front, giving Dembele the space and creative freedom to thrive.

"We expected a game with a lot of intensity played at a high rhythm," Xavi said. "We knew they would press high, so we put in another midfielder to outnumber them through the middle. We wanted an extra man in midfield. I think the key, though, was that we matched them in intensity."

The hosts scored three times in 10 minutes in the first half, starting with Dembele's towering header from close range in the 12th minute.

The France forward then put Roberto through with some brilliant one touch build-up play in the 18th minute, with the Spanish full back's strike bouncing in off a defender past a helpless Unai Simon.

Four minutes later, Dembele ran down the right channel before crossing to Lewandowski who swivelled and finished with a powerful shot.

After thumping Villarreal in midweek, Barca were well on their way to another victory. However, there was concern for midfielder Gavi who was in tears when substituted midway through the first half, having received a knock to his groin area.

The 18-year-old has become an important part of Xavi's side and is also a key component of the Spain squad heading to the World Cup in Qatar next month.

"It looks like it's not serious. It was a hard blow to the muscle, but we have to wait until tomorrow for the medical test," Xavi said after the match. "Dembele was as brilliant as all our players up front have been performing. I have great faith in our team going forward."

Barca took their foot off the gas after the break but there was still time for Dembele to deliver another assist less than 20 minutes before the end, playing the ball in from the left touchline for Torres to score from close range.

We weren't close to winning, that's clear," Valverded said after the match. "Barca were strong. We tried, at the start, pressing high. They played through it well and punished us. In 10 minutes, three goals. The second kills us a little.

"I was surprised by Barca's system. playing with four midfielders and opening the pitch with [Alex] Balde and Dembele. It caught us out a little."