The Brazil playmaker was linked with a move to Chelsea before Friday's transfer deadline but showed his commitment to the Barca cause with a virtuoso display which proved too good for Athletic.

Ronaldinho's double gave the hosts a commanding half-time lead and although Markel Susaeta pulled one back, Yaya Toure's first goal for Frank Rijkaard's side settled the contest.

Both sides finished with 10 men with Barca's Rafael Marquez and Athletic's Lertxundi Koikili seeing red.

Barcelona started well and took the lead after eight minutes through a stunning free-kick from Ronaldinho.

The former Paris St Germain star was tripped on the edge of the box and stepped up to curl an exquisite effort into the top corner to put the Catalans in front.

Three minutes later, Ronaldinho almost scored a second from a similar position, but this time saw his effort sail just over the bar.

Barcelona's dominance was almost total at this stage and Gianluca Zambrotta got forward well to test former Espanyol keeper Gorka Iraizoz with an angled drive after 21 minutes.

Thierry Henry, making his home debut, then almost got on the end of a Deco cross after 27 minutes as Barcelona continued to press forward.

Four minutes later, the Frenchman won a penalty after going down following a challenge with Iraizoz.

Following treatment to the Athletic goalkeeper, Ronaldinho stepped up to double his side's lead and put Barcelona in control with half-time approaching.

Lionel Messi could have made it three just before the interval, but sent his effort just wide after Ronaldinho's neat pass.

Susaeta tried his luck at the other end, but his long-range effort was comfortably gathered by Victor Valdes.

Barcelona took a while to settle after the break and Athletic almost capitalised after 53 minutes when substitute Ion Velez found himself one-on-one with Valdes.

The young striker appeared to freeze, however, and the chance was lost.

That narrow escape was followed by a few jeers of discontent from the home crowd, unhappy at their side's insistence on playing the ball around at the back.

The grumbles of disapproval seemed to spark the Catalans back into life once again and Henry, as he had done on his debut in Santander, struck the post following a one-two with France team-mate Eric Abidal.

It was the former Arsenal striker's last contribution as he was promptly replaced by Mexican forward Giovani Dos Santos shortly after the hour mark.

The youngster, making his competitive debut following an exhilarating performance in Wednesday's friendly against Internazionale, proceeded to waste a glorious opportunity eight minutes later.

Messi tormented Ustaritz Aldekoaotalora on the left before squaring for the Mexican, who failed to hit the target from 10 yards out.

Two minutes later, Barcelona were punished for that miss when Susaeta fired home from close range after hesitation in the Catalan rearguard.

Rijkaard's side immediately restored their two-goal advantage in controversial fashion, when Toure's crashing drive bounced off the crossbar and onto the goal line.

After consulting with his assistant, referee Carlos Megia Davila awarded the strike, which did not appear to cross the line.

Athletic were furious but were given some respite four minutes later when Marquez was sent off for a second bookable offence.

However, the Basques' numerical advantage lasted only three minutes as Bilbao full-back Lertxundi was also dismissed following a bad tackle on Dos Santos.

Messi and Toure both tried their luck as full-time approached while Aritz Aduriz almost grabbed a late consolation for the visitors but Barcelona were good value for a victory which leaves them on four points after two rounds.