Barcelona responded to the La Liga title challenge thrown down by Real Madrid with a Lionel Messi-inspired 4-1 win at home to Celta Vigo.
La Blaugrana went back above Real Madrid at full time, following their 4-0 win at Eibar earlier.
Barcelona reacted to their 3-1 defeat at Levante last weekend in style, with Messi at this incredible best at the Camp Nou.
Celta worked hard to keep Barca at bay in the opening stages, but they were undone on 23 minutes.
Defender Joseph Aidoo conceded a penalty for handball, and Messi slotted home with no fuss.
Ernesto Valverde's side looked to build from there, with Celta keeper Ruben Blanco saving from Messi and Antoine Griezmann.
However, despite their early dominance, Barcelona were shocked by Celta equaliser on 42 minutes.
Lucas Olaza stepped up to whip an unstoppable free kick into the top corner.
But with home crowd stunned, Messi edged Barcelona back in front in added time before the break.
Perhaps spurred on by Olaza's effort, the Barca skipper arrowed a trademark free kick past Blanco.
That gave he hosts a boost for the second half, and Messi shocked the crowd again by repeating his trick three minutes after the restart.
The 31-year bulleted an almost carbon copy of his first free kick to restore their two- goal advantage and seal his first hat trick of the season.
Celta looked to battle back from there, but substitute Sergio Busquets sealed the win five minutes from time, as the Spanish international netted a low drive for his first goal in over two years.
