Barcelona's march towards the Primera Liga title slowed on Saturday after a goalless draw at bottom side Malaga, although second-placed Osasuna failed to capitalise �s they lost 1-0 away to Athletic Bilbao.

With an eye on Tuesday's Champions League quarter-final away to Benfica Barca coach Frank Rijkaard sent out an experimental lineup that dominated but was never really convincing.

Barca had a goal ruled out in the first half and Samuel Eto'o hit the bar at the end, while Malaga goalkeeper Francesc Arnau made a string of impressive saves.

The draw saw leaders Barcelona move 13 points clear of Osasuna on 68 points after Bilbao defender Luis Prieto headed the only goal of the game in an intense encounter in San Mames.

Both sides finished with 10 men after Osasuna's Ludovic Delporte and Bilbao's Ismael Urzaiz were sent off at the end.

Third-placed Real Madrid [Images], on 54 points, are at home to Deportivo Coruna on Sunday when Valencia, a further point behind in fourth, visit fifth-placed Sevilla.

Earlier, two first half goals from Brazilian striker Robert gave Real Betis a surprise 2-1 win at eighth-placed Villarreal.

Robert scored a superb diving header, and then pounced on an error in the defence for the second.

Villarreal, who travel to Inter Milan in a Champions League quarter-final on Wednesday, pulled a goal back through Argentine midfielder Juan Pablo Sorin 11 minutes from time and were denied a penalty in the last move of the game.

The win dragged an improving Betis five points above the relegation zone up to 13th, level with Bilbao on 33 points.

GOAL DISALLOWED

Barcelona had an unfamiliar look about them in Malaga with Ronaldinho [Images] rested, captain Carles Puyol suspended, and Edmilson, Rafael Marquez and Lionel Messi [Images] injured.

Rijkaard even left Deco on the bench and it showed as Barca laboured throughout against a side battling to avoid relegation.

Arnau saved well at his far post from Henrik Larsson's close range header early on, but chances were hard to come by in the first half.

Malaga were keen to test the visitors' rookie central defensive pairing of Oleguer and Rodri, and after 29 minutes Fernando Sanz rose to head straight at Victor Valdes as they struggled to clear a cross.

Seven minutes before the break Eto'o put the ball in the net as a free kick broke free in the Malaga area, but the referee ruled it out for a handball by Larsson in the build up when the ball in fact struck Malaga defender Cesar Navas on the arm.

Arnau denied Giuly, Larsson and Eto'o early in the second half as Barca stepped up a gear but Malaga steadily grew in confidence as the game opened out.

A nervy final few minutes saw Eto'o draw a fine save from Arnau while Duda replied at the other end, forcing Valdes to scramble across to his far post to save a shot from distance.

In injury time an attempted clearance in the Malaga area ballooned into the air and Eto'o let fly with a fierce volley that crashed against the bar and bounced out to be cleared.

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