A shell-shocked Amelie Mauresmo had the Australian Open trophy ripped from her grasp on Sunday by a teenage upstart who had won only one grand slam match before arriving at Melbourne Park.

Lucie Safarova played the match of her life to shatter Mauresmo's title hopes in the fourth round with a 6-4, 6-3 win.

As the 19-year-old Czech sealed the defending champion's fate in the 89th minute and held her arms aloft to lap up the applause from the hollering fans, a forlorn Mauresmo was left to digest her worst showing in Australia since losing in the fourth round in 2001.

"It's amazing I still can't believe it. I'm so happy, it's incredible," a stunned Safarova told the crowd.

"It's the first time I 'm playing on Rod Laver Arena and in the morning I thought wow this is a big court."

Shahar Peer continued a day of upsets as she became the first Israeli woman to reach the quarter-finals of a major when she humbled Russian third seed Svetlana Kuznetsova 6-4, 6-2.

In the Czech camp, a double celebration was being planned for Sunday night after Safarova's boyfriend, 13th seed Tomas Berdych, humiliated Russian Dmitry Tursunov 6-2, 6-1, 6-1 to reach the last 16.

But the day belonged to Safarova.

For a woman ranked 70th in the world and who had never before experienced the imposing surroundings of the Rod Laver Arena, Safarova initially seemed overawed by the occasion and predictably fell 4-1 behind to Mauresmo.

With the first set within her grasp, the second seed imploded and lost seven successive games as the left-handed Safarova sprayed a non-stop array of winners from the baseline.

SUPER WOMAN

The Frenchwoman had said before the start of the tournament, "I hope I'll be Super Woman in the next two weeks." On Sunday she could have done with some super powers as she simply could not find an answer to Safarova's blistering strokes.

The second set was almost a mirror image of the first, except it was Safarova who had galloped to a 4-1 lead as Mauresmo struggled to stem the flow of errors flying off her racket.

Although Mauresmo claimed back one of the breaks, it was not enough to deny Safarova victory. Mauresmo surrendered her maiden grand slam title with a netted error.

Kuznetsova had been in a three-way tussle with Mauresmo and Maria Sharapova to wrest the world number one ranking from Justine Henin-Hardenne at the end of the tournament.

But like Mauresmo, Kusnetsova's chances of climbing to the top ended unceremoniously.

The Russian smacked a forehand into the net to end a 77-minute ordeal on Vodafone Arena, leaving a jubilant Peer to go and exchange high-fives with her support team.

Li Na's record-breaking run on the tennis circuit continued when she became the first Chinese player to reach the fourth round of the singles draw at Melbourne Park.

A quarter-finalist at Wimbledon last year, she upset Russian ninth seed Dinara Safina 6-2, 6-2 and will run into three-times former champion Martina Hingis next.