Roof shuts after Federer show

Roger Federer remained the epitome of cool, Venus and Serena Williams hurtled towards another final showdown and Centre Court's new roof finally closed as showers interrupted a heatwave at Wimbledon.

After the mercury had shot past 30 degrees to herald the tournament's second Monday, grey clouds rolled in, raindrops fell and world number one Dinara Safina fought back to beat former champion Amelie Mauresmo in the first competitive match to be played under the gleaming canopy.

Safina was leading 4-1 in the second set, having dropped the first, when tournament referee Andrew Jarrett made the call to close the roof, a decision greeted with cheers from the crowd inside the 15,000-seat arena.

After a 40-minute break while the air conditioning system kicked in, the Russian returned to win 4-6 6-3 6-4 despite trailing 3-0 in the decider.

"It was an unbelievable atmosphere on the court," Safina, who will play unfancied German Sabine Lisicki in her first Wimbledon quarter-final, told reporters.

Five-times champion Federer, bidding for his own slice of history by winning a record 15th grand slam, nailed Sweden's Robin Soderling, the man he beat in this month's French Open final. In scorching temperatures the Swiss won what he later described as a "serving contest" 6-4 7-6 7-6.

With forecasters predicting even higher temperatures in the coming days in south west London, the Williams sisters, who have faced each other three times in the women's singles final here, were able to conserve precious energy.

Second seed Serena, beaten in last year's final by her older sister, thrashed Slovakia's Daniela Hantuchova 6-3 6-1 while Venus was required to play just eight games to get past Serb Ana Ivanovic, who quit with a thigh injury after little more than half an hour on Court One.

Impressive fourth seed Elena Dementieva, a semi-finalist last year, polished off fellow Russian Elena Vesnina while Italy's Francesca Schiavone beat Virginie Razzano of France.

There is a sense of inevitability about another Williams family showdown on Saturday. They simply look unstoppable.

Venus now has Agnieszka Radwanska in her sights after the Pole ended the run of 17-year-old American Melanie Oudin 6-4 7-5.

Serena belted 28 winners on her way to a quarter-final against Belarussian Victoria Azarenka.

Federer will need body armour in the next round when he takes on towering Croat Ivo Karlovic who took his ace tally for the tournament to 137 in a four-set defeat of Spain's Fernando Verdasco to reach his first grand slam quarter-final.

Germany's Tommy Haas, the oldest player in the last 16, reached the last eight for the first time, outwitting Russia's Igor Andreev 7-6 6-4 6-4 to set up a quarter-final against fourth seed Novak Djokovic, who beat Israel's Dudi Sela.

Lleyton Hewitt, who like Haas has fought back from serious injury, produced the comeback of the day to delight his vocal fans. The 2002 champion looked to be heading out before hitting back to win 4-6 2-6 6-1 6-2 6-2.

Hewitt meets American Andy Roddick for a semi-final spot after the American's surprisingly straightforward straight-sets removal of dangerous Czech Tomas Berdych.

Other result: Murray bt Wawrinka 2-6 6-3 6-3 5-7 6-3.