Although the visitors enjoyed the better of the possession for long periods it was the hosts who carved out the clearer chances, Barcelona managing just two shots on target during the match.
Munian converted Markel Susaeta’s pinpoint cross with 20 minutes of the match remaining before Gaizka Toquero squandered a great chance to double his side’s lead, Pinto pulling off a terrific reaction save.
It is only the second time that Barcelona have failed to score for the second time in 71 league matches and defeat means that they are level on points with Athletico Madrid and only three ahead of great rivals Real Madrid.
Victory means that Bilbao are still unbeaten at their new San Mames home.
Barcelona started brightly and the first decent chance fell to Neymar as Alexis laid it back into his path, Iraizoz pulling off a fingertip save to touch his strike over the bar.
Neymar then crashed a shot against the post only to see the flag raised for offside but the Brazilian then struggled with his footwear, slipping regularly on the slick San Mames surface and he required a change of boots.
Despite Barca dominating possession, it was the home side who carved out the better chances in the opening half and Muniain should have put them ahead when Susaeta’s cross fell to him two yards out but he fluffed his shot straight at Pinto.
Barca started the second half as they did the first and Neymar really ought to have put them ahead from Fabregas’s fine ball but the Brazilian leaned back and fire his shot well over.
And if he had decided to stay on his feet instead of going to ground on the edge of the box only minutes later, he may have put his side level.
Bilbao were not so wasteful: Munian buried his second clear-cut opportunity and although Toquero should have made the game safe, the home side held out for a famous win.
- Sports & Recreation
- Iker Muniain
- La Liga