Xavi Hernandez's injury-time equalizer brought FC Barcelona a 1-1 draw with Valencia in the Copa del Rey semifinal first leg on Wednesday.
Samuel Eto'o appeared to handle before firing a shot which was parried by Valencia goalkeeper Timo Hildebrand and midfielder Xavi drove in the rebound.
Striker David Villa gave the visitors the lead in the 70th minute when he turned home a low cross from the right by substitute Javier Arizmendi, giving Valencia a slight advantage for the second leg at its Mestalla Stadium on March 19 or 20.
Valencia's draw made for a satisfactory return to Camp Nou for coach Ronald Koeman, who helped Barcelona win the 1992 Champions League final by scoring the winning goal against Sampdoria at Wembley.
Barcelona, whose draw extend its unbeaten run in all competitions to 15 matches, is aiming to add to its record 24 triumphs in Spain's knockout competition, the last of which came a decade ago.
In the other semifinal on Thursday, Getafe bids to boost its hopes of repeating last season's debut appearance in the final when it hosts Racing Santander.
The final will be played on April 16 at an as yet unspecified venue.
Barcelona's lineup featured France striker Thierry Henry and Portugal midfielder Deco although Ronaldinho was rested.
Valencia started with its two recent midfield signings, Hedwiges Maduro and Ever Banega.
Barcelona struggled to create chances before halftime although it almost took an early lead when Xavi, Eto'o and Lionel Messi all had goalbound shots blocked in quick succession in the sixth minute.
From then on, Valencia's tight defense frustrated Barcelona, with only long-range shots from Henry and defender Eric Abidal forcing Hildebrand into saves.
Messi, emerging as Barcelona's most dangerous player, spurned a good chance in the 50th minute when he side-footed tamely for Hildebrand to make a comfortable save.
Hildebrand denied Messi again in the 58th and Eto'o in the 67th, moments before Barcelona coach Frank Rijkaard brought on teenage striker Bojan Krkic and midfielder Andres Iniesta in place of Henry and Deco respectively. At the same time, Koeman swapped Banega for Ruben Baraja.
Trailing with 20 minutes remaining, Barcelona's attacks grew in urgency and Hildebrand was required to thwart Messi and Iniesta in the 80th.
Barcelona's Gabriel Milito's low shot was tipped away by the diving Hildebrand in the 84th and his defensive partner Gianluca Zambrotta blazed wide a minute later.
Hildebrand again kept his team ahead in the 89th when he saved Yaya Toure's curling shot.