The visitors were not finished as they regained the lead through Paco Alcacer just before the hour mark, and that proved to be decisive as they picked up a famous victory in Catalonia.
Here, Sports Mole dissects the 90 minutes of action between the two La Liga rivals.
On target: 5
On target: 4
Was the result fair?
Looking at the statistics, it is difficult to argue that Valencia deserved to pick up all the points, but they must be credited for their response after struggling in the first period. In truth, a draw would have been just about a reflection of the match, but take nothing away from the visitors.
There is no question that the Spanish champions should have had this match sewn up at the interval. Valencia simply could not cope for long periods in the first half, but missed opportunities cost Barca. Their defensive frailties were shown in the second half, however, with the visitors threatening time after time on the counter. Too many of their attacking players had quiet afternoons, but credit must be given to Valencia.
Perhaps Valencia would have been forgiven for falling to a two or three-goal loss after conceding early on, but they showed incredible character to turn the match around. Usually when Barcelona are beaten, it can be argued that the victors were fortunate, but that was not the case this afternoon. It was a performance that radiated hard work and desire.
Sports Mole's man of the match
Sofiane Feghouli: The 24-year-old, who has been deployed in a number of positions this season, was terrific this afternoon in an advanced midfield role. Not only did the Algerian produce two assists, but he was also always prepared to help out in defensive areas.
Barcelona entered the match boasting the best defensive record in La Liga, but their back four was all over the place this afternoon. Too often Jordi Alba and Daniel Alves were caught high up the pitch, which made it easy for Valencia to counter.
Pedro Perez had a relatively straightforward first period - issuing just the one yellow card to Parejo with neither side committing too many fouls. There was certainly more bite to the match in the second half, but his decision to award Barca a penalty for a Ricardo Costa handball was a touch harsh.
Barcelona: The Catalan outfit are in Copa del Rey action on Wednesday as they host Real Sociedad in the first leg of the semi-finals.
Valencia: Valencia will attempt to build on this result when they welcome basement outfit Real Betis in La Liga next weekend.