By Pritha Sarkar

MELBOURNE (Reuters) - 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.

On a day when Russian seeds Svetlana Kuznetsova, Elena Dementieva and Dinara Safina were also hustled out, 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 after 89 minutes 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 by becoming the first Israeli woman to reach the quarter-finals of a grand slam when she humbled third seed Kuznetsova 6-4 6-2.

Seventh seed Dementieva's fragile serve was once again exposed during a 6-3 6-3 defeat by Czech Nicole Vaidisova, who at 10th is now the highest seed left in the bottom half of the draw.

DANGEROUS FLOATER

Serena Williams lived up to her status as a dangerous floater in the field as she claimed the scalp of in-form Serbian 11th seed Jelena Jankovic with a 6-3 6-2 hammering.

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

Sixth seed Andy Roddick ensured coach Jimmy Connors would not have to endure a wasted trip by subduing the firepower of big-serving Croatian Mario Ancic 6-3 3-6 6-1 5-7 6-4 in the fourth round.

"I wasn't very comfortable there today... I was lucky to get through today," Roddick said.

But the day belonged to Safarova.

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

With the first set nearly in 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 Superwoman 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 galloped to a 4-1 lead as Mauresmo struggled to stem the flow of errors flying off her racket.

Although Mauresmo claimed back one break, it was not enough to deny Safarova victory and the Frenchwoman 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 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, Li completed a terrible day for the Russians when she upstaged ninth seed Safina 6-2 6-2 and will next run into three-times former champion Martina Hingis.