Roger Federer remained the epitome of cool as temperatures soared and Venus and Serena Williams hurtled toward another final showdown in Wimbledon's second week.

Five-time champion Federer nailed Sweden's Robin Soderling, the man he beat in this month's French Open final, in what he described as a "serving contest," winning 6-4, 7-6, 7-6 to ease ominously into the quarterfinals.

Soderling, the man who ended Rafael Nadal's 31-match winning streak at Roland Garros, is a dangerous beast on grass with a huge serve and whiplash forehand but as in Paris he found the 14-time grand slam champion just too good at the vital moments.

The Swede only lost his serve once in the entire match but faltered in both tiebreaks.

"I think today was just a serving contest, not too many rallies," said Federer, who can eclipse Pete Sampras on Sunday by collecting a 15th slam. "Today was hard to get through. Robin served great, thank goodness he served a double fault at the end of the tie-break because it could have been four sets."

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.

The Williams sisters, who have faced each other three times in the final here, were able to conserve energy.

Second seed Serena, beaten last year 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 tearful Serb Ana Ivanovic, who quit with a thigh injury after little more than half an hour on Court 1.

"I think she was in a lot of pain," the 29-year-old Venus, gunning for a hat-trick of singles titles here and her sixth in total, told reporters.

"I'm one of those players who only pays attention to what's going on my side of the net. But today I felt really sad for her actually."

Fourth seed Elena Dementieva, a semifinalist last year, polished off fellow Russian Elena Vesnina quickly to become the first player through to the last eight.

Whatever the form of their rivals - world No. 1 Dinara Safina was in action later in the day against Amelie Mauresmo - there is a sense of inevitability about another Williams family showdown on Saturday. They simply look unstoppable on the slick Wimbledon lawns.

"I'm a control freak," added Venus who now has Agnieszka Radwanska in her sights after the Pole ended the run of 17-year-old American Melanie Oudin 6-4 7-5.

"I love controlling. That's how I was taught to play."

(Agencies via Shanghai Daily June 30, 2009)