Top seed Rafael Nadal [Images] shrugged off an interruption from a female spectator, who handcuffed herself to the net post, to reach the quarter-finals of the Barcelona Open on Thursday.

While third seed Guillermo Coria double-faulted his way out of the tournament and 2002 French Open champion Albert Costa bowed out of professional tennis, Nadal extended his winning streak on clay to 44 matches with a 6-4, 6-2 win over Spanish qualifier Ivan Navarro Pastor.

Nadal was more bothered by the intruder than his opponent.

The young girl, wearing a white mask and a T-shirt campaigning for Catalan independence, ran on to the court and handcuffed herself to the net post when Nadal was leading 6-4, 4-0.

After a brief delay, the girl was led away and Nadal eased to victory and a quarter-final against Finn Jarkko Nieminen.

"It was bad for me because I was leading 4-0 and 0-30 and then I lost that game," Nadal said.

"But I don't like this -- I don't think it is very good for the whole tournament."

Third seed Coria was hammered 6-2, 6-0 by Spaniard Nicolas Almagro, the Argentine producing 14 double faults and winning just six points in the second set.

FIX PROBLEMS

Coria, who served 23 double faults in one match in Monte Carlo last week, said he was working hard to fix his problems.

"I have had problems on my serve ever since my operation (August, 2004) and I know it is not back to where it was," the world number nine said.

"It is all about confidence. But I am working with (coach) Jose (Higueras) and I hope that in three or four weeks I will be playing at a high level again.

"The good thing is that if I am still winning matches when I am giving away so many gifts, then that shows my basic game is good."

In the quarter-finals, the 57th-ranked Almagro will face 10th seed Juan Carlos Ferrero after the Spaniard beat his compatriot Albert Costa 6-1, 5-7, 7-5.

Costa had recorded wins over Vince Spadea and eighth seed Dominik Hrbaty in the previous rounds but was unable to repeat the feat against his successor as Roland Garros champion.

Ferrero snatched the vital break in the 11th game of the decider before serving out for victory.

The two friends embraced at the net after the match and the 30-year-old Costa received a standing ovation.

Costa won 12 career titles and helped Spain to win the Davis Cup for the first time in their history in 2000.

Fifth seed David Ferrer was another Spaniard to exit when he lost to Swiss Stanislas Wawrinka 2-6 6-2 6-1.

Wawrinka will next play big-serving Croatian Ivo Karlovic who ended the run of Russian qualifier Evgeny Korolev 6-7, 7-6, 7-6.

Czech Radek Stepanek beat Frenchman Paul-Henri Mathieu 1-6, 6-3, 6-2. He will meet sixth seed Tommy Robredo or unseeded Spaniard Fernando Verdasco.

Robredo was leading 2-1 with a break of serve in the third set when rain stopped play.

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