Roger Federer and Andy Murray were locked on collision course at the Australian Open Monday as an unstoppable Serena Williams powered towards her third straight Grand Slam title. As Novak Djokovic regrouped after his late-night thriller against Stanislas Wawrinka, Federer and Murray had no such problems as they breezed into the quarter-finals.

Murray had the simplest of tasks against a weakened Gilles Simon, still struggling after his marathon win over Gael Monfils, while Federer easily had the weapons to deal with the machine-gun serve of Milos Raonic. Federer, playing in the showpiece evening match on Rod Laver Arena, needed a solitary break to edge the first set, and then won tiebreaker for the second before he swept through the last to take it 6-4, 7-6 (7/4), 6-2.

The Swiss master, now into his 35th consecutive Grand Slam quarter-final and seeking his 18th major title, said "good reflexes" were the key to coping with Raonic's bullet serve. "You try to anticipate a bit, and it happened better and better as the match went on," he said. "It's important to stay focused. I have learned that over the years, and it pays off in the end."

While defending champion Djokovic battled to recover from his five-hour, five-set win which concluded in the early hours of Monday, Simon was still struggling from his marathon victory over Gael Monfils a day earlier. The Frenchman, who could hardly walk after wrapping up the five-setter post-midnight, was in no state to face US Open champion Murray, and he quickly went down 6-3, 6-1, 6-3, calling it "a painful hour-and-a-half."

"Yesterday I was just biking 20 minutes, you know, stretching, massage, cold bath. I did everything I could," said Simon. "But it's difficult when you run a marathon two days before to go for one more two days after." Murray called it a "tough situation" but he admitted his mind was already on his next match, a quarter-final with France's world number 36 Jeremy Chardy. The Briton is scheduled to face Federer in the semi-finals.

"I felt after the first few games, because he wasn't serving hard at all, you know, his forehand side wasn't moving that well either," said Murray of Simon. "It was just about trying to finish the match as quickly as I could and then getting ready for the next one."

Chardy, who comes from the same coaching stable as Williams, reached his first Grand Slam quarter-final with a straight-sets defeat of Italian Andreas Seppi. He had never previously gone past the second round in Melbourne. Jo-Wilfried Tsonga, buoyed by new coach Roger Rasheed, beat Richard Gasquet in four sets to tee up a quarter-final against Federer.

Meanwhile the women's competition hotted up as Williams ran over a stunned Maria Kirilenko 6-2, 6-0 and her potential semi-final opponent, title-holder Victoria Azarenka, dominated Elena Vesnina 6-1, 6-1. Williams dispatched Kirilenko in less than an hour as she reached her 35th Grand Slam quarter-final and set up a last-eight clash with fellow American Sloane Stephens, 19, who beat Serbia's Bojana Jovanovski.

"I haven't beaten Serena and I hope I'll give you all a good show," said the confident teenager. Russian veteran Svetlana Kuznetsova, a two-time Grand Slam winner, missed much of last season with injury but she said the break had done her good as she returned and beat ex-number one Caroline Wozniacki in three sets. She said: "After 10 years of travelling I was getting tired. But I'm feeling fresh again and very happy to be in the quarter-finals because I struggled last year." In Wednesday's quarter-finals, Kuznetsova will meet last year's champion Azarenka.