Madrid: A promising Real Sociedad side matched Barcelona in San Sebastian to earn a 2-2 draw in a pulsating game on Saturday. (Agencies)
The home team came back from a two-goal first half deficit to share the points and provide the first challenge of the season to Barcelona's domination of the Spanish league.
Barca seemed to have the game wrapped up early with two early goals within a minute from Xavi Hernandez and Cesc Fabregas.
However, a sterling second half performance from Sociedad saw them level the game with goals on 57 and 59 minutes from Imanol Agirretxe and Antoine Griezmann.
Barca coach Pep Guardiola suprised all with his starting eleven, leaving Leo Messi, Andres Iniesta and David Villa on the bench.
All three came from international duty in midweek and with one eye on the Champions League opener at home to Milan on Tuesday night Barcelona were able to show their strength in depth early on.
They started strongly and it was no surprise when Barca went ahead in the tenth minute.
Fabregas floated a superb pass to Alexis Sanchez from the right channel and he squared the ball to Xavi for an easy finish from 10 yards out.
A minute later it was Fabregas who finished from close range at the second attempt after an almost identical pass from Xavi from the left hand channel.
Villa came off the bench on the half hour as new signing Sanchez was stretchered off with what looked to be a muscular problem.
With Barca completely dominant at this stage it looked like another large scoreline was on the cards.
The Catalans were content to play their passing game for what remained of the first half.
But it was a different Real Sociedad who came out in the second half and Imanol Agirretxe got the home team back in the game on 57 minutes with a powerful header from a Xabi Prieto cross.
Two minutes later it was Agirretxe again who rounded Barcelona goalkeeper Victor Valdes and hit the crossbar to allow Griezmann to head home from point blank range.
With the match all square Messi appeared from the bench to replace Thiago Alcantara but Barcelona rarely threatened as the home team finished stronger.
It was only left for Messi to receive a yellow card in the final minute for diving on a disappointing afternoon for himself and Barcelona.
Meanwhile in the other early kick off on Saturday, Villarreal put up a brave performance with ten men to draw 2-2 with Sevilla in an entertaining match in front of Spanish coach Vicente del Bosque.
When Villarreal substitute Marco Ruben finished powerfully on 72 minutes he seemed to have won a game between two teams who will challenge for European positions again this season.
However, Sevilla centre half Alexis Ruano appeared to head home and earn a point for Sevilla with five minutes remaining.
After making a fantastic save on 15 minutes from Manu del Moral, Villarreal goalkeeper Diego Lopez felled Diego Perotti and was red carded in the 21st minute.
Reserve goalkeeper Cesar Sanchez replaced Cani in time to save Alvaro Negredo's weak penalty but was not able to stop Negredo's follow up from a tight angle.
After a period of pressure from Sevilla it was Villarreal who squared the scoreline in the 23rd minute.
Again the goal came from the penalty spot after Fernando Navarro stopped Giuseppi Rossi's mazy run with a trip. The US International picked himself up to finish coolly.
Sensing victory Villarreal coach Juan Carlos Garrido introduced Ruben and he seemed to have won it with his strike until Alexis' late header.
Madrid: A promising Real Sociedad side matched Barcelona in San Sebastian to earn a 2-2 draw in a pulsating game on Saturday.