Lionel Messi scored his first goal of the season as Barcelona beat Sevilla 4-0 on Sunday to climb into second place in the La Liga standings behind Real Madrid, but ended the game with nine men as Ousmane Dembele and debutant Ronald Araujo were sent off.
The victory saw Barca leapfrog Atletico Madrid into second place on 16 points, two behind leaders Real who they meet in three weeks at the Camp Nou. Atleti are third on 15 after drawing 0-0 at Real Valladolid on Sunday.
The Catalans rode their luck in the early stages of the game as Julen Lopetegui's Sevilla made an ambitious start but failed to take their chances while Barca were ruthlessly efficient and scored three times in the space of eight first-half minutes.
Luis Suarez gave the champions the lead with an outstanding bicycle kick in the 27th minute and Chile midfielder Arturo Vidal then got a crucial touch on a tame shot from Arthur Melo to double Barcelona's lead in the 32nd.
Dembele, who was named in the starting lineup ahead of €120 million ($131.76m) signing Antoine Griezmann, made it 3-0 in the 35th with a superb solo dribble and finish.
Barca captain Messi scored from a free kick in the 78th to finally get off the mark in a season which has been blighted by injuries but there was a sour end to the game for Ernesto Valverde's side, who are two points behind Real.
Uruguayan defender Araujo had made his debut by replacing the injured Jean-Clair Todibo but was sent off 14 minutes later for a last-ditch challenge on Javier Hernandez, while Dembele was dismissed for protesting the decision.
Barca's goalscorer Vidal made no apologies for his side's winning margin.
"We were superior to them the whole time, we were always putting them under pressure and we are worthy winners," he told reporters.
"We were up against a team who are good with the ball and on the wings but we dominated them in those areas."
Lopetegui's last visit to the Camp Nou was a painful affair as his Real Madrid side were hammered 5-1 by Barca in his final game in charge before being sacked, and this was a similarly galling experience for the former Spain coach.
His Sevilla side created three clear chances to take the lead at the Camp Nou but missed them all, as Dutch striker Luuk de Jong was thwarted by Barca keeper Marc-Andre ter Stegen and then missed the target, as did Brazilian midfielder Fernando.
The luckless De Jong then had a chance to strike back for his side early in the second half but hit the post, one of 16 attempts for Lopetegui's side, who hit the target only four times. Barca had 15 shots, hitting the target eight times.
"We started the game very well but once we went behind it was very difficult for us," said Sevilla's Fernando.
"We had so many chances to score, but if you switch off for one second at the Camp Nou you get punished."