Joao Felix and Joao Cancelo scored their first Barcelona goals as the reigning La Liga champions swatted aside Real Betis on Saturday night to take top spot before title rivals Real Madrid play this weekend.
Joao Felix put Barca ahead with his first goal for the club before Robert Lewandowski doubled their advantage from Andreas Christensen's pass.
Ferran Torres' smart free kick, a fine effort for Raphinha and another debut goal - this time from Joao Cancelo - in the second half helped the Blaugrana complete a comprehensive thrashing of Manuel Pellegrini's Betis at Estadi Olimpic Lluis Companys.
It takes Barca to first in La Liga before Real Madrid take on Real Sociedad on Sunday evening.
How the game unfolded
Barca went into Saturday night's clash looking to usurp Madrid at the top of La Liga but surrendered the game's first big chance to the visitors.
Jules Kounde lost Isco, who found Willian Jose before the ball arrived at the feet of Luiz Henrique. However, the 22-year-old Brazilian's shot from a tight angle just outside the six-yard box flashed past the bottom corner.
A Betis free kick came close to providing the game's first goal soon after as Ayoze Perez controlled the ball and lashed into Marc-Andre ter Stegen's side-netting.
That first goal came midway through the first half and fell Barca's way as the Catalan giants pressed well to win the ball high before Oriol Romeu swung a cross into the box towards Joao Felix. The loan arrival from Atletico Madrid mis-kicked on the first attempt but retained possession to finish smartly from a tight angle.
It was Felix's first goal for Barca and helped settle his new side down before a well-worked second from Lewandowski further cemented their grip on the game.
Andreas Christensen stepped out of defence and fired a pass forward towards Felix, who dummied over the ball to allow it to find Lewandowski. The Poland international ran through and tucked in his third La Liga goal of the season.
Barca were firmly in control by half-time and after Felix had another effort disallowed for offside, Xavi's side further extended their lead through the in-form Torres.
The Spain international took charge of a free kick and curled it around the outside of the Betis wall, catching substitute goalie Francisco Vieites napping at the near post.
By the 66th minute, Raphinha had joined the party by scoring his first league goal of the season. The Brazil international pitched up on the edge of the box soon after his introduction from the bench and collected Lewandowski's pass, reversing a powerful shot into the opposite corner.
With Betis well and truly beaten, there was time for Cancelo to join Felix in netting his first goal for Barca. The Portugal right-back sauntered forward with the visitors stretched and put Juan Miranda on his backside before driving in his side's fifth.
Barcelona player ratings (4-3-3)
GK: Marc-Andre ter Stegen - 7/10 - Accurate distribution out from the back and made a few smart stops, in particular from Willian Jose.
RB: Joao Cancelo - 9/10 - Gave Miranda a torrid time with dribble after dribble before smashing in his new side's fifth.
CB: Jules Kounde - 7/10 - Looked a little vulnerable as Betis pushed early on but settled into more of a rhythm as Barca became more dominant throughout the contest.
CB: Andreas Christensen - 7/10 - Nice pass assisted Lewandowski - albeit with Felix's dummy helping out. Taken off with around 15 minutes left.
LB: Alejandro Balde - 7/10 - Another energetic display at left-back from Balde, who was a constant outlet down the left. A little loose in possession.
CM: Frenkie de Jong - 8/10 - Made 102 accurate passes - 30 more than the next highest - being readily available for the ball while darting forward when the opportunity came.
CM: Oriol Romeu - 6/10 - Managed a somewhat fortunate assist for Felix but wasn't as big a defensive presence as he has been so far at Barca.
CM: Gavi - 7/10 - Seven successful tackles for the young Spain international, who attempted 12 in total. Also good on the ball, misplacing only two of his 51 passes.
RW: Ferran Torres - 8/10 - Torres' resurgence continues with his third league goal of the season after netting twice against Cyprus on international duty. Took his chance on his first start and will hope to stay in the XI in midweek Champions League action.
ST: Robert Lewandowski - 8/10 - Rubber-stamped Barca's grip on the game with their second and picked up two assists in the second half.
LW: Joao Felix - 8/10 - Gave a performance more befitting of the hype around his earlier career, linking up well with teammates and scoring his first Barca goal on the second attempt.
Raphinha (64' for Torres) - 8/10 - Scored only two minutes after his introduction from the bench, adding to Xaxi's selection dilemma in attack.
Lamine Yamal (64' for Felix) - 6/10 - The record-breaking Spain international had a quiet game off the bench.
Ilkay Gundogan (64' for Romeu) - 6/10 - Quite a player to merely keep things ticking over for the final 30 minutes of an already-secured victory.
Inigo Martinez (76' for Christense) - 5/10 - Booked after coming on for the final exchanges.
Marcos Alonso (76' for Balde) - 5/10
Subs not used: Inaki Pena, Sergi Roberto, Ander Astralaga (GK), Marc Casado, Unai Hernandez.
Xavi - 8/10 - A few early Betis opportunities aside, Barca were dominant, creating all the major chances and showing great clinical edge in the final third. Without a few key players in Ronald Araujo and Pedri, Xavi led Barca to a large and straightforward win.