Luis Suarez struck the only goal of the game as Barcelona began their Primera Division title defence with a 1-0 victory at Athletic Bilbao.
The fixture was the third in succession between the two teams after Athletic had embarrassed Barca 5-1 on aggregate in the Spanish Supercopa.
However, unlike nine days ago, when the hosts won 4-0 at San Mames, reigning Spanish and European champions Barca were far less erratic and, crucially, through Luis Suarez, scored the game's only goal.
Perhaps surprisingly given the recent history between the two sides in which Athletic's high intensity and pressing had been key to winning their first trophy in 31 years, Barca's opening to the game resembled a pre-season friendly.
There was a focus on possession and little else, and certainly minimal urgency, at least for the opening 30 minutes until they were awarded a penalty.
Athletic's Gorka Elustondo misjudged a bouncing ball, allowed Suarez to take possession and then felled him in the penalty area. The decision may have been harsh given he also appeared to win the ball, too, but goalkeeper Gorka Iraizoz reacted well in diving low to his right to push Lionel Messi's softly-struck penalty wide.
Suarez, typically, was again involved five minutes later when his close-range shot, from Sergi Roberto's cross, was saved by Iraizoz before Rafinha struck the rebound across goal in the final notable effort of the first half.
Nine minutes after the restart the Uruguay forward gave Barca the lead. Full-back Jordi Alba sent a high cross into Athletic's penalty area and Suarez, blessed with an abundance of both time and space from directly in front of goal, sent a well-struck, left-footed volley beyond Iraizoz.
It took a further 23 minutes for Athletic to truly threaten and when they did, through Aritz Aduriz - their inspiration when winning the SuperCopa - playing in Markel Susaeta, the latter could only shoot harmlessly hide and wide.
In the final five minutes Suarez again sent the ball into the back of the net, with an exceptional 30-yard chip, but he was judged to be offside from Messi's pass and what would have been a fine goal was therefore disallowed.
Messi almost immediately forced a save from Iraizoz with a weak shot having impressively dribbled past several defenders, though a goal eluded him on an evening when he was below his exceptional best.
Meanwhile, Barca's arch-rivals and main title rivals Real Madrid were unable to give new boss Rafael Benitez a winning start as they were held to a frustrating 0-0 draw by newly-promoted Sporting Gijon at El Molinon.
Ahead of the match Benitez faced questions about a possible goalscoring problem for his side after they failed to net in four of their eight pre-season friendlies, but the Spaniard was confident they would put any debate to bed against Sporting.
However, despite having 25 shots on goal compared to just five from Sporting, Madrid's star-studded side failed to find the breakthrough.
And they might even have ended up returning empty-handed from their trip to the north coast had Sporting striker Antonio Sanabria's first-half header crossed the line after crashing down off the underside of the bar, rather than bouncing out.
