Barcelona dropped two points to newly-promoted Levante while Atletico Madrid heaped more misery on Real Betis.
Barca boss Frank Rijkaard was without a number of his star players, although the Catalan giants nearly claimed all three points.
The visitors were ahead at half-time thanks to Deco's fine free-kick that struck the post and flew into the net.
Barca were inches from going two-up, however, Santiago Ezquerro's deft shot was palmed onto the post by Jose Molina.
Levante snatched a share of the spoils on 77 minutes when Alvaro tapped home after Victor Valdes spilled Olivier Kapo's free-kick.
Real Betis missed a great chance to pull away from the drop zone after missing two penalties in their 1-0 loss to Atletico Madrid.
The visitors showed the home side how to finish when Luciano Galletti fired a right-footed effort into the roof of the net from close range.
Betis had a great chance to level matters when they were awarded a penalty following Luis Perea's challenge on Rafael Sorbis.
However, Leo Franco made a double save from Edu's spot-kick to maintain Atletico's slender lead.
Betis amazingly had another penalty for Giourkas Seitaridis' push in the box, although again Betis missed, this time Fernando's tame effort was kept out.
The win sees Atletico climb up to fourth in La Liga while Betis stay 17th with just two league wins to their name.
Elsewhere, Recreativo de Huelva got the better of Valencia with a 2-0 win.
An early goal from Aitor Tornavaca set the home side on their way just two minutes in.
Recreativo had to wait until the closing stages before Florent Sinama-Pongolle settled the contest.