The Catalan side may have lost the domestic Super Cup to Real Madrid in midweek but they have now picked up maximum points from their first three league games that keeps them top of the table.
It also maintained their five-point lead over defending champions Real, who earlier beat Granada 3-0, Cristiano Ronaldo hitting a brace to reach a landmark 150 goals in 149 games for the capital club.
Barca full-back Adriano's drive from outside the area after 23 minutes was the only goal of the game at the Nou Camp against a Valencia side who battled hard but spent most of the game defending deeply.
Former Arsenal midfielder Alex Song made his first start in a Barca shirt with Sergio Busquets rested and played alongside Xavi Hernandez and Cesc Fabregas who returned to the starting line-up.
Roberto Soldado went within inches of giving Valencia the lead after 11 minutes with a 25-yard strike which whistled past the post.
Lionel Messi had a header saved by keeper Diego Alves after 18 minutes but the Valencia shot-stopper could do nothing about Adriano's sweetly struck drive minutes later.
There may have been a change of coach in the summer with the departure of Pep Guardiola and the arrival of Tito Vilanova but the football has remained the same and Barca knocked the ball around inside the Valencia half in trademark fashion.
Cesc had the opportunity to extend the lead but with time in the box after receiving the ball from Messi he dinked the ball wide. It has been a disappointing start to the campaign for Cesc and after the restart he blazed over from in front of goal.
Valencia were hanging on but without a second goal Barca could not relax and had their hearts in their mouth several times especially when Victor Ruiz put the ball in the back of the net on the hour mark but was ruled off-side.
Earlier in the evening, Cristiano Ronaldo hit a brace to help Real Madrid get their league campaign back against 10-man Granada.
Despite their cup win the pressure was starting to grow on the team with just a point from their opening two league games but Ronaldo responded with a goal in either half to continue his remarkable scoring run in Madrid.
The first owed as much to poor keeping from Antonio 'Tono' Rodriguez as the Portuguese's shot from a tight angle after 25 minutes went through his legs, although it did take a slight deflection off Inigo Lopez.
Ronaldo got his second after 53 minutes and Granada's hopes of a comeback took a blow with Borja Gomez sent off six minutes later. Substitute Gonzalo Higuain completed the scoring with a tap-in 15 minutes from the end.
Still Real lacked fluidity in their passing which Jose Mourinho pointed out afterwards.
"I did not like the game as we had little rhythm. We have had little time to work this week and we were slow. We got the points but that is not enough, we have to play better," he said.
Luka Modric was given a starting place after he came on for the last few minutes against Barca and threaded the ball through to Jose Callejon inside the first few minutes but ‘keeper Tono got down well to block him.
Ronaldo had looked sluggish in his first two league games and he failed to trouble the 'keeper with a free-kick and a couple of shots from distance before he did break the deadlock with a soft goal from Granada's perspective.
The visitors had shown nothing going forward and were now forced to come out of their shells but it was Ronaldo that could have added a second before the break with a drive which Tono was alert to.
Angel Di Maria came on after half time and he set up Ronaldo, who saw his shot from inside the box saved by Tono before reacting to knock home the rebound.
Gomez was given his second yellow card for a foul on Ronaldo and then Higuain sealed the win from a Benzema pass.
Earlier Rayo Vallecano drew 0-0 with Sevilla and Athletic Bilbao overcame Valladolid 2-0, while Levante dramatically came from behind to beat Espanyol 3-2, with defender Raul Rodriguez deflecting the ball into his own net in time added on to decide the game in the home side's favour.
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