David Villa's goal four minutes into the second half gave his side a 1-0 win at home to a brave Sporting Gijon.
Villa accepted a pass from Dani Alves, before firing a right foot shot into the far corner of the Sporting goal.
Barcelona controlled 80 percent of the ball, but their failure to score a second goal left the home fans calling for the final whistle.
Barca coach Pep Guardiola decided to bring Bojan Krkic and Seydou Keita into his starting 11 and rest defender Gerard Pique.
Sporting meanwhile rested several first team regulars following their home game against Athletic Club at the weekend.
It was a bright start with Sporting keeper Pichu Cuellar making saves from David Villa and Andres Iniesta.
Villa hit the side netting and Keita saw a shot from outside of the area saved, but Sporting looked generally comfortable before the break.
Guardiola brought Pedro Rodriguez and Pique into the game at halftime and was rewarded by Villa's goal.
The Spain international began his career with Sporting and refused to celebrate his goal.
Barcelona was in control, with around 80 percent of the possession of the ball, but failed to score a second goal and the fans ended up asking for the final whistle.
Valencia lost their 100 percent record, but came back from a goal down to draw 1-1 at home to Atletico Madrid. Simao scored for the visitors, but Aduriz leveled the score in the closing minutes.
Elsewhere, Levante won their first game of the season as Sergio's 39th minute goal gave them a 1-0 win away to a toothless Almeria.
Finally Zaragoza's poor start to the campaign began with a dreadful 0-0 draw at home to Hercules. Jarosic's shot against the post for the home side was the high point of the game.
Tuesday saw Real Madrid beat Espanyol 3-0. while Athletic Club Bilbao won 3-1 at home to Mallorca and Osasuna claimed a 3-1 win against Real Sociedad.