The Brazilian struck the decisive blow a minute before half-time with a left-footed effort that Malaga goalkeeper Willy Caballero will have been disappointed to see slip through his grasp. (Agencies)
However, Malaga were left to rue two huge chances after the break as firstly Fabrice struck the post and then Sebastian Fernandez headed straight at Victor Valdes when completely unmarked inside the area in the closing stages.
And Cesc Fabregas admitted that going forward the Catalans will need to improve on their performance in the second period. "The first-half was very good and we could have scored more," he said.
"In the second it is true that we lost a bit of our intensity due to tiredness from the game on Wednesday,” he added.
"In the last five minutes we struggled but sometimes you have to do that. It was a hard-fought and important victory," Fabregas said.
Despite Messi's absence, Barca boss Gerardo Martino once again started with Neymar on the bench as Fabregas replaced the Argentine, whilst Alex Song and Adriano replaced Sergio Busquets and Dani Alves from the side that started Wednesday's 1-1 draw with Atletico Madrid in the first-leg of the Spanish Super Cup.
Without either of their South American attacking stars, Barca's build-up play was somewhat ponderous in the first period as they failed to break down a solid but limited Malaga side.
Andres Iniesta then fired an effort from the edge of the area straight down Caballero's throat, but the Argentine was forced into a stunning save nine minutes before the break as he blocked Alexis Sanchez's header from point-blank range.
However, Caballero was slightly at fault when Barca did eventually take the lead as Adriano cut inside onto his left foot and his curling effort flew over the Malaga keeper's outstretched arm on its way into the far corner.
The Brazilian struck the decisive blow a minute before half-time with a left-footed effort that Malaga goalkeeper Willy Caballero will have been disappointed to see slip through his grasp.