Ivan Rakitic's firm header steered Barcelona to a 1-0 victory away to Athletic Bilbao as Luis Enrique's champions made it two wins from two in La Liga.
The Catalan giants are still without the talents of Neymar and Andres Iniesta, but still had enough quality to resist strong opposition from Athletic at San Mames.
It was not as spectacular as the opening 6-2 success over Real Betis at the Nou Camp, but Lionel Messi and company were a constant menace on the break. Luis Suarez almost scored a second in deep in added time, but he was denied by a goal-line clearance from Eneko Boveda.
Arda Turan had a goal ruled out in the fifth minute for offside, and Marc-Andre ter Stegen's 'sweeper keeper' approach was almost the undoing of Barca in the 12th minute when he rolled the ball straight into the path of Benat Etxebarria. Luckily for the visitors, the German goalkeeper was able to block Benat's shot with his chin.
However, it was Barca who opened the scoring after 20 minutes as Turan was released down the left by Suarez in a swift breakaway, cut back on to his right foot and his cross picked out Rakitic racing into the box to head past Gorka Iraizoz from six yards.
Ter Stegen was called on twice to keep out shots on target from Aritz Aduriz and Benat as the half entered its final five minutes, but Barca gave a reminder of their ability to break at lightning speed just before the whistle blew.
Messi slotted the ball into the path of Turan, but he could only find the side-netting as he tried to steer a low shot beyond Iraizoz.
The mercurial Argentinian was the first to go close in the second period, shifting the ball on to his left foot on the edge of the area but drilling just wide of Iraizoz's right-hand post.
Suarez then volleyed wide in the 57th minute after a great cross from the right by Sergi Roberto picked him out unmarked.
Athletic were still in it and had chances to level when substitute Raul Garcia dragged a right-foot shot wide and the lively Inaki Williams poked a shot straight at Ter Stegen after 65 minutes.
Messi fired a chance over the bar in the 70th minute after Sergio Busquets' alert pass released Turan down the left.
Sergi Roberto tried to play in Suarez with nine minutes left but, despite getting the better of first Boveda and then Aymeric Laporte, he fired wildly across goal after finally making space to shoot.
The single-goal lead made for a nervy conclusion to the game and Benat went close with a curling free-kick which brushed the side-netting.
Barca had one final chance as Messi broke clear and opted to square the ball to Suarez, but Boveda had tracked back and stretched to block the Uruguayan's injury-time effort.