The reigning Liga champions were given a stern test of their credentials but prevailed thanks to the Brazilian defender
The defender's goal towards the end of the first period meant Barca extended its 100 percent league start after thrashing Levante 7-0 last weekend.
A fine save by Willy Caballero tipped Gerard Pique's effort on to the crossbar as Barca pushed for a second that failed to materialize, although by the end it was thankful for a late Victor Valdes save that ensured it claimed all three points.
Gerardo Martino was without the injured Lionel Messi for the encounter, while Neymar had to be content with a place on the bench. Poland striker Bartlomiej Pawlowski made his starting debut for Malaga, who were missing Eliseu and Flavio Ferreira.
A Cesc Fabregas through ball after 18 minutes almost paved the way for an early opener at La Rosaleda but Pedro's poor first touch took the ball out of his stride.
The Liga champions enjoyed particular joy down Malaga's left-hand side, as Xavi and Andres Iniesta looked to combine to control the midfield exchanges and unleash Alexis Sanchez into the wide areas.
The hosts spent long periods without possession, but when they had the ball, they were quick to try and work it into the final third.
A long-range direct free kick just before the half-hour mark forced Valdes into action for the first time in the match but he safely dealt with Vitorino Antunes' ambitious effort.
The deadlock was deservedly broken after 43 minutes, though, as Adriano curled a long-range, left-foot effort past the helpless Caballero after good buildup play from Sanchez.
Barca looked more than comfortable after the break, dictating the play in similar fashion to the first half. Malaga struggled to create any openings of real substance, as the visitors repeatedly threatened to double their lead.
Pique forced a spectacular save from Caballero with a free kick on 57 minutes, with the keeper tipping the ball onto the crossbar.
Martino then introduced Neymar into proceedings as the visitors pressed for that elusive second goal, and the Brazilian almost got on the end of an inviting Dani Alves cross.
Fabrice Olinga then went close to a leveler just past the hour mark against the run of play. After excellent counter-attacking down the left wing by Roque Santa Cruz, the striker's stabbed effort rebounded off the post.
A free kick from substitute Neymar again forced a save from Caballero, with the goalkeeper having to beat the ball away after it took a deflection off the wall.
But Barca was thankful for Valdes's late heroics as he kept out Sebastian Fernandez's header from an inswinging cross from Jesus Gamez.