First half goals from Leo Messi and Gerard Pique gave FC Barcelona a vital win away to Atletico Madrid in the Vicente Calderon Stadium.
The win put an end to Atletico's 100 percent start to the season and ended a positive week for Barcelona, who have bounced back from last week's shock defeat to Hercules in positive style.
Pep Guardiola's team won 5-1 at home to Panathinaikos in the Champions League on Tuesday night and this win shows they are back to their best.
It also showed they know how to dig deep against a rival that left the result in doubt until the last instant.
Atletico Madrid striker Kun Aguero was finally passed fit to start the game after being a doubt with knee problems all week. Barcelona were without defender Eric Abidal, however, after he had to leave the squad because of an illness in his family.
Atletico's Vicente Calderon Stadium was packed with 55,000 fans hoping to see their side achieve a fourth consecutive home win against the Catalans.
Barcelona opened the scoring after 13 minutes. David Villa was put through on goal and although his shot hit the post, Messi was on hand to flick the ball over David de Gea.
He was close to doubling the lead 10 minutes later, but failed to get a good contact on Dani Alves' diagonal ball.
Atletico were level after 25 minutes as Raul Garcia out-jumped the Barca defense to head home Simao's corner.
The goal gave the home side a breath of air and Alves was booked for a challenge on Simao, although from the resulting free kick it was Barcelona that created the chance as Messi ran upfield with the ball, which was scrambled wide for a corner.
Pique then took advantage of some poor marking to put Barca back ahead, controlling with his chest before scoring with a volley.
Atletico tried to pressure Barcelona high up the park, but the visitors were controlling the ball and Villa was inches away from setting Messi up for a second goal before the break.
Xavi Hernandez went close with a shot from distance after half time, but De Gea produced a flying save.
The game was becoming bogged down in midfield and Atletico coach Quique Sanchez Flores opted to replace Garcia with Thiago, but Barcelona continued to create the best chances with Villa a constant threat, although Messi missed a guilt edged chance to seal the points five minutes from time.
Atletico defender Ujfalusi was sent off for a foul on the Argentinean deep into injury time. Messi was carried off on a stretcher, but by then the game was won.