Barcelona completed a wretched week when they surrendered the leadership of the Primera Liga to arch-rivals Real Madrid after they were held to a 1-1 draw at home to Real Betis on Sunday.
Barca, who saw their double dreams go up in smoke when they were given a 4-0 mauling by Bernd Schuster's Getafe in the King's Cup in midweek, looked to be heading for a nervous win after Ronaldinho gave them an early lead from the penalty spot.
But Betis dashed their hopes of returning to the top of the top of the table when Brazilian striker Rafael Sobis took advantage of some shaky defending to drill home at the near post two minutes from time.
The result means that with four games left to play Real and Barca are level on 66 points but the nine times European champions top the standings by virtue of their better head-to-head record against the Catalans.
It is the first time that Real have ended a round of matches at the top of the table since October 2005.
Real staged a dramatic fightback to come from 3-1 down to snatch a 4-3 win at home to Espanyol on Saturday thanks to a last-gasp strike from Argentine forward Gonzalo Higuain.
Sevilla are in third spot, just two points behind the leaders, after they warmed up for Wednesday's all-Spanish UEFA Cup final against Espanyol with a 2-1 win over Recreativo Huelva on Saturday.
