Federer, Kerber stunned as Nadal powers into Open quarters

Defending champion Roger Federer was stunned by fiery Greek Stefanos Tsitsipas who ended his bid for a record seventh Australian Open Sunday on a day of upsets that also saw second seed Angelique Kerber crash out.

The Swiss master caved in under the energy and pressure of a man 17 years his junior to tumble out 6-7 (11/13), 7-6 (7/3), 7-5, 7-6 (7/5) in the last 16 on Rod Laver Arena.

World number two Kerber was also sensationally bundled out by a woman playing the event for the first time, with American Danielle Collins humiliating the Wimbledon champion 6-0, 6-2 in under an hour.

The man Federer beat in last year's final, sixth seed Marin Cilic, was also sent packing by Spain's Roberto Bautista Agut, who now plays Tsitsipas in the quarter-finals.

Five-time Grand Slam winner Maria Shaparova was another to fall, but there was no such drama for a rampant Rafael Nadal who powered into the last eight with a straight sets win over Tomas Berdych.

Federer was gunning for a 21st Grand Slam title but had a battle on his hands from off against the 20-year-old, touted among the new generation of young stars as a future champion.

"I'm the happiest man on Earth right now, I cannot describe it," said the 14th seed, who is the first Greek in history to reach the quarter-finals of a Slam.

"I've been idolising him (Federer) since the age of six. It was a dream come true for me just being on Rod Laver facing him. Winning at the end, I can't describe it." The Swiss great was gracious in defeat, saying "I lost to a better player who was playing very well, who hung in there and stayed calm".

Wimbledon winner and 2016 champion Kerber, the bookies' favourite along with Serena Williams after defending champion Caroline Wozniacki was ousted early, was no match for Collins, ranked 35 in the world.

Collins is little known after playing much of her tennis in the US college system and was making her debut in the main draw at Melbourne Park. She had never won a Grand Slam match before this year.

"I may not have won a Grand Slam match before this but I tell you, it's going to keep happening," said the 25-year-old. "I better have many more of these." - Chipping away -
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