Powering through

Roger Federer and Serena Williams beat the weather and their opponents to storm into the quarter-finals of the US Open and send an ominous warning to the current world number ones about their intentions for the last grand slam of the year.

It was just likes old times for the greatest players of their generation as they turned in masterful displays on a day when Novak Djokovic and Caroline Wozniacki both toiled but survived on Monday night.

Federer demolished Argentine baseliner Juan Monaco 6-1, 6-2, 6-0 in a fourth round clash that began just before midnight but ended before an approaching storm drenched Flushing Meadows.

Williams, playing during the day when the wind was blowing hard, breezed past Serbia's Ana Ivanovic 6-3, 6-4 to close in on what could be the greatest achievement of her incredible career.

Wozniacki won a late-night thriller against former champion Svetlana Kuznetsova of Russia 6-7, 7-5, 6-1, dispelling the notion that she lacks the predatory instincts to land her first major. Facing an early exit after losing the first set in a tiebreaker then falling behind 4-1 in the second, she won 12 of the last 14 games and looked as fit at the end as she did at the start.

“I could have played another two or three sets if I had to,” the Danish top seed said. Her next match is against Germany's Andrea Petkovic, who defeated Carla Suarez Navarro of Spain 6-1, 6-4, with Williams looming in the semis. Djokovic also showed his fighting qualities to win a 30-point tiebreaker in his 7-6 (14), 6-4, 6-2 victory over Ukraine's Alexandr Dolgopolov to reach the last eight without dropping a single set.

Djokovic's next opponent is his Davis Cup team mate Janko Tipsarevic, who beat former world number one Juan Carlos Ferrero of Spain 7-5, 6-7, 7-5, 6-2 in a slugfest that lasted almost four hours. “It means there's going to be at least one Serbian in the semi-finals, which is great for our country,” Djokovic said.

Federer reached his 30th straight slam quarters.