Frank Rijkaard's side were thrashed 4-0 by Getafe on Thursday and things went from bad to worse as Betis battled back to seal an undeserved draw and seriously threaten the Catalans' hopes of a third successive league title.

Ronaldinho put Barcelona ahead from the spot after three minutes, but fellow Brazilian Rafael Sobis equalised for the Andalusians a minute from time to provoke the fury of the home supporters, many of whom waved white handkerchieves to show their disgust at their team's performance.

Rijkaard recalled Victor Valdes in goal and Argentinian forward Lionel Messi up front after both were rested against Getafe.

Portugal midfielder Deco also returned and won a penalty for Barcelona after just three minutes.

The Brazil-born playmaker was upended by defender Juan Alberto Melli and Ronaldinho stepped up to fire the spot-kick past Pedro Contreras and into the right-hand corner to give Barca an early lead.

Germany winger David Odonkor went down in the opposite area two minutes later, but was adjudged to have dived and duly picked up a yellow card.

Dutch full-back Giovanni van Bronckhorst then almost set up Samuel Eto'o after 10 minutes, but the Cameroonian could not quite connect and the chance was lost.

Eto'o was heavily involved in all of Barcelona's good work and sent a header just wide in the 23rd minute.

Five minutes later, the African teed up Xavi, but the Spain midfielder could not get his shot on target.

Eto'o then saw his brilliant bicycle-kick acrobatically saved by Contreras and also shot just over the bar after an explosive run.

Andres Iniesta should have put the Catalans two ahead shortly afterwards, in the 39th minute.

The diminutive midfielder flicked Messi's square-pass beyond his marker, but sliced wide with just Contreras to beat.

Barcelona had totally dominated the first half, but only had one goal to show for their superiority and Betis almost equalised just before the interval.

Lilian Thuram gave the ball away in his area and Fernando forced Valdes into a quick reaction save which preserved the home side's lead at the break.

When the action resumed, Messi chipped harmlessly over the bar with Barcelona continuing to attack as they had done in the first period.

But Betis tightened up and the hosts struggled to move forward until Brazilian full-back Juliano Belletti flashed a dangerous ball across the six-yard box in the 58th minute.

Eight minutes later, Eto'o evaded his marker with an audacious flick, but fired his rasping volley straight at Contreras from outside the area.

Ronaldinho was then replaced by Edmilson and Messi made way for Javier Saviola as Rijkaard looked to sew up the victory.

As time ticked away, Eto'o blasted a right-footed shot well over the bar after Iniesta had charged down the right flank and squared for the Cameroonian to shoot from the edge of the area.

But when the game's second goal finally came, it went to Betis.

The Andalusians took a quick free-kick and Rafael Sobis fired a powerful shot past a stagnant Valdes at the near post to leave the Nou Camp in shock.

Despite the goal, Barcelona quickly regrouped and almost grabbed a late winner when Iniesta blasted just over from eight yards.

Deco also fired inches over the crossbar in the dying seconds and his look of frustration summed up the mood in the stadium.

Barca and Madrid have 66 points with four games remaining.