Real Sociedad produced the first major surprise of the Spanish football season as they fought back from 2-0 down to claim a 2-2 draw at home to FC Barcelona. The Basque side had looked to be out of it at the break as they fell behind to goals from Xavi Hernandez and Cesc Fabrigas and only managed one shot on target in the first 45 minutes. However, a fine fightback led by striker Imanol Agirretxe, who scored one goal and set up Antoine Griezmann for the second saw the home team take a well deserved share of the points. Barcelona coach Pep Guardiola produced several surprises in his starting 11, which Andreu Fontas partnering Sergio Busquets in defense, while Cesc tarted alongside Hernandez and Seydou Keita in midfield, while Leo Messi was on the substitutes\' bench. Barcelona\'s tactics were easy to see with Alexis Sanchez and Pedro Rodriguez opening up the full width of the pitch and Cesc looking to get onto a pass over the Real Sociedad defense, which was defending high up the pitch. The home side were working hard, but Barcelona always looked likely to exploit the space behind the defense and they struck twice in just over a minute. On 10 minutes, Cesc lifted the ball over the top for Alexis to control and squad for Xavi to slide the ball into an open net to open the scoring, before it was Xavi\'s turn to return the favor, setting to Cesc, who ceded to Pedro. Although Pedro\'s shot was saved by Claudio Bravo, Cesc was on hand to score from the rebound. It wasn\'t all good news for Barcelona, however, and the Catalans lost Alexis with a possible hamstring injury just after the half hour following a challenge from Real Sociedad defender Dani Estrada. Alexis was carried off and replaced by David Villa. Tests later showed he could be out for six to eight weeks. Real Sociedad had only one shot on target in the first half, but drew level on the hour as Agirretxe headed home a Xabi Prieto cross. The striker found space behind Busquets and planted a firm header past Victor Valdes. A minute later the home side were level. Villa\'s attempted backpass was intercepted by Agirretxe and although his shot was tipped onto the bar by Busquets, who was lucky not to be sent off, the rebound fell for Griezmann to head home from close range. Both sides looked for the winning goal, but Barcelona especially looked unlikely to score and their frustration was evident when Messi, who came on after the equalizer, was booked in injury time for diving to try and win a penalty.