The Catalan giants dropped to third in the table after Atleti and Real Madrid won ahead of their Camp Nou fixture, but reclaimed their place at the summit with a thoroughly convincing performance on Sunday.
After consecutive league draws against Atleti and Levante – the first time Barca had gone two league games without winning since May 2011 – Gerardo Martino's side dominated the first half and took the lead through Gerard Pique in the 40th minute, his second goal in as many matches.
Barca would have led by more if it were not for the brilliance of Malaga goalkeeper Willy Caballero, but goals from Pedro and Alexis Sanchez in the first 20 minutes of the second half sealed the result.
Lionel Messi did not score, as his league scoring drought extended to 120 days, but new president Josep Maria Bartomeu, watching from the stands, would not have minded as Barca dominated from start to finish.
They remain goal difference ahead of Atletico, who had star midfielder Arda Turan score a double.
David Villa opened the scoring for Diego Simeone's side in the eighth minute before Rayo Vallecano missed a chance to equalise from the penalty spot.
Jonathan Viera's penalty was well saved by Atletico goalkeeper Thibaut Courtois in the 12th minute, and Turan opened his account on the half-hour mark to make them pay.
Viera tried to make amends for his miss with a goal six minutes before the break but Turan restored their two-goal advantage on the stroke of half-time.
A Saul Niguez own goal put Atletico 4-1 ahead, meaning Joaquin Larrivey's late goal meant little.
Athletic Bilbao also won well on the road, thrashing a 10-man Osasuna 5-1 to move five points clear in fourth.
Markel Susaeta's third-minute goal gave Athletic the lead, and although Emiliano Armenteros levelled, Aritz Aduriz put the winners back in front in the 16th minute.
Aduriz added a second in the second half before Alejandro Arribas was sent off for a second yellow card, with substitutes Ibai Gomez and Kike Sola compounding their misery with late goals.
And in Sunday's other match, Almeria beat Getafe 1-0 thanks to Jonathan Zongo's second-half strike.
