Two goals in the space of a few minutes helped Barcelona come from behind to keep their faint title hopes alive.
Bilbao led just after half-time when Artiz Adruiz slipped the ball past Pinto.
But a tap-in from Pedro and a costless-kick from Lionel Messi ensured Barcelona would record their first win since their 3-1 success over Real Betis.
Tata Martino had called on Barcelona to 'fight till the end' after they were knocked out of the both cup competitions in a week, losing to Atletico in the Champions League and Real Madrid in the Copa Del Rey final.
It was far from an easy win for Barcelona as they were left frustrated by an inspired performance from Gorka Iraizoz who made a number of impressive saves from Messi, Pedro and Alexis.
It was also an eye-catching performance from Aritz Adruiz, who boosted his chances of making the Spain squad.
In the first half he nearly scored one of the goals of the season but the post denied his overhead kick.
He did get reward for his persistence on 50 minutes as he gave Bilbao the lead after getting the better of Pinto.
It appeared Barcelona were resigned to defeat and their problems were shown by the disapproval from the crowd when Cesc Fabregas came on as a substitute for Xavi.
However, Barcelona found a way back into the game when Pedro turned in Alexis Sanchez's shot from close range.
Then Messi converted a costless-kick from inside the D to complete the turn around for the Catalans.
The win leaves Barcelona four points off Atletico Madrid with four games to play.
The title is very much alive and it appears as though it will come down to the match between Barcelona and Atletico on the final day of the season.