Both sides went into the match with 100 percent records and Valencia looked on track to keep theirs when striker David Villa scored his fourth goal against Barcelona in three matches as he swept onto a perfect pass from Portugese defender Miguel and steered the ball home.
However the champions rose to the challenge and equalized in the second half as substitute Andres Iniesta was on hand to benefit from stunning lead up front from Ronaldinho and Samuel Eto'o.
The draw though meant that Valencia were able to extend their unbeaten run at the Nou Camp with their last defeat there occurring back in 2001.
The only other side with a perfect record, Sevilla, lost for the first time in any competition since April when they were defeated 2-1 by an inform Athletico Madrid.
The UEFA Cup champions looked to be on track for another win when midfielder Renato scored late in the first half.
But the match took a dramatic turn in the second half when Sevilla had both centre backs, Julien Escude and Javi Navarro sent off.
Despite then defending doggedly Argentinean midfielder Maxi Rodriguez scored twice in the final five minutes to snatch all three points for the home side.
Last season's Champions League semi-finalists Villareal scored their first goals of the season in their 3-2 win at home to Real Zaragoza.
Giant Serbian striker Nikola Zigic scored twice as Racing Santander gained their first points of the season in their 2-2 draw with Gimnastic de Tarragona.
While a double from former Juventus midfielder Olivier Kapo saw Levante hand Deportivo La Coruna their first defeat of the campaign.