Seydou Keita was the unlikely hero for Barcelona as his goal edged the Spanish champions past Real Zaragoza and ten points clear at the top of La Liga.
Keita struck two minutes before the break after Lionel Messi's cross fell to him seven yards from goal and he swept it low into the net to give the Catalans a 1-0 victory at the Nou Camp.
Barcelona carved out a succession of chances but couldn't find what would have been a decisive second, as Zaragoza offered them little danger on the counter attack.
It signalled a fourth straight victory for Pep Guardiola's side who again extended the gap between themselves and Real Madrid in second. Jose Mourinho's men can close to within seven points when they take on Racing Santander on Sunday.
Villarreal had their hopes of breaking into the top three of the Primera Division checked by a 3-1 defeat to Atletico Madrid at the Vicente Calderon.
Jose Antonio Reyes got the ball rolling after five minutes for Atletico before the dangerous Giuseppe Rossi brought parity to proceedings 10 minutes before half-time. Atletico's highly-rated front two of Diego Forlan and Sergio Aguero then made their presence felt, scoring within four minutes of each other to ensure the home win.
Pablo Hernandez struck both goals as Valencia came from behind to win 2-1 against Real Mallorca to ensure they would finish the weekend still in third place in the standings.
Mallorca took a 31st-minute lead through an Ivan Ramis penalty but Valencia needed just two minutes to get back on level terms thanks to Pablo, who then struck the winning goal 11 minutes into the second half.
The victory means Valencia, who lost 1-0 at home to Barcelona on Wednesday, provisionally moved four points clear of fourth-placed Villarreal, who face a tough game at Atletico Madrid later on Saturday.
Mallorca, meanwhile, missed the chance to climb to within one point of the European places after slumping to their third defeat in four games.