Updated

Already guaranteed of occupying the top two positions on the WTA singles ranking next week, Serena and Venus Williams are now challenging to be the top ranked doubles team in the world.

That was the incentive that sent them out on a ridiculously cold May evening here in the Madrid Masters to beat Shahar Peer and Francesca Schiavone 7-5, 6-2 after Venus put an end to Samantha Stosur's fine clay-court run by beating the Australian 6-3, 6-3.

The doubles win put the Williams sisters into the final where they will meet Gisela Dulko and Flavia Pennetta late on Saturday evening, while earlier in the day Venus will be playing Peer once again in the first of the day's singles semifinals. The Czech, Lucie Safarova and Aravane Rezai of France will be competing in the second following the improving Rezai's upset win over No. 7 seed Jelena Jankovic.

Venus is in a pretty good mood at the moment: "I'm enjoying the challenge of playing on clay," she said. "I like my job, I like my career, I like my life, I like my dog." She finished in peels of laughter as her enthusiasm ran away with her.

But she was serious in analyzing a match in which both players went for their shots behind big serves. Stosur, who is maybe paying the penalty of winning all the time -- so many matches and so little time to recover -- was forced into submission for only the second time this year on clay and there was nothing much she could do about it against this kind of dynamic opposition.

"I don't change my game much," said Venus. "For me to change is tough, especially on pressure points. In those moments I have to go with what I know. Of course there are adjustments you have to make. You have to respect the surface. But I do play my game, hitting big serves, playing aggressively."

How many times have critics suggested that Venus's enthusiasm for her sport is waning? How many times has she proved them wrong? She is fit, keen and focused right now which means that either she or her sister can win any tournament they enter.

Roger Federer is feeling quite pleased with life at the moment, too. He feels he has been hitting the ball cleanly all week and that enabled him to stage an impressive comeback against the precocious 21-year-old Latvian Ernests Gulbis, who had beaten him in Rome last week. Gulbis, serving well and hitting the ball with tremendous power, led by a set and a break before Federer turned things around with an outrageous lob and never looked back. The final score of 3-6, 6-1, 6-4 reflected the way in which the Swiss was able to impose his free-flowing game on a dangerous opponent.

"I was able to go on a tear and win six games in a row," said Federer. "I was happy with the way I managed to read his serve and mix the game up a bit."

Federer -- the defending champion here -- will now play David Ferrer, who ran himself into the ground in an extraordinary duel with Andy Murray before beating the Scot 7-5, 6-3 in a match that was far closer than the score suggests. Murray battled with enormous grit and no little skill in an attempt to find a way through the Spanish defences in a series of rallies that frequently lasted more than twenty strokes. The first two games of the second set took 27 minutes but, in the end, Murray was forced to admit that, on clay, Ferrer had all the answers.

Earlier Rafael Nadal had kept his fans happy with a 6-1, 6-3 defeat of Gael Monfils. The Frenchman is normally a threat on clay but he is still trying to get back into his stride after injury and did not play a good match. Several double faults didn't help and the tactic of trying to change the pace of his potentially lethal forehand backfired. Give Rafa anything slow and inviting to hit and he murders it.

Nadal will now meet fellow Spaniard Nicolas Almagro who defeated the Austrian left-hander Jurgen Melzer 6-3, 6-1.