MELBOURNE, Australia — Top-seeded Jelena Jankovic was knocked out in the fourth round of the Australian Open, and will have to search elsewhere for her first Grand Slam title.

Frenchwoman Marion Bartoli, the 2007 Wimbledon finalist, broke Jankovic's serve twice in the first set en route to a 6-1, 6-4 win Sunday and a place in the quarterfinals.

"I tried to not think about it for the whole match," Bartoli said of Jankovic's No. 1 ranking. "This is my first time playing in Rod Laver Arena. I think I just played amazingly today and I'm so glad to put on a good performance."

The 16th-seeded Bartoli had not been past the second round in seven previous trips to Melbourne Park.

Critics questioned whether Jankovic could convert her numeric ranking into a victory in the championship match at a major. She was a semifinalist at the Australian Open and French Opens last year before losing the U.S. Open final to Serena Williams.

When Bartoli turned up the pressure Sunday, Jankovic tightened up again.

Bartoli was the aggressor, repeatedly sending Jankovic serves back faster than they came over and standing two steps inside the baseline for second serves.

Bartoli hits two-fisted, flat and hard from both sides, and she peppered the lines and corners. Jankovic, repeatedly covering her face or looking to her mother for support and guidance, seemed shellshocked after falling behind 5-0 in the first set despite shouts of "Let's go JJ!" from the crowd.

Jankovic fended off two set points while serving at 1-5, but Bartoli easily held in the next game, finishing off the set with a deft drop shot that caught Jankovic behind the baseline.

Increasingly tentative and bewildered, Jankovic twice lost points early in the second set by stopping play on Bartoli shots that she thought were long but replays showed caught the line. She used up her last challenge of the set in the sixth game.

Bartoli broke to pull ahead 5-4 in a game that went to deuce six times, with Jankovic netting a backhand on breakpoint.

Jankovic wanted to challenge Bartoli's winner in the next game but couldn't. The Frenchwoman went on to hold despite a twitchy double fault at 40-15, whacking a forehand winner down the line and raising her arms in jubilation.

Last Saturday night, men's No. 1 Rafael Nadal ripped 53 winners in a 6-4, 6-2, 6-2 victory against Tommy Haas.

Nadal kept his unforced errors to a frugal eight — and to just one in the 43-minute second set.

"I played one of my best matches here at the Australian Open," said Nadal, who has improved by one round in each of his five trips to Australia. To continue that sequence, he'll have to make the final.

Andy Murray won 11 straight games during a 7-5, 6-0, 6-3 win over Austrian Jurgen Melzer.

And the 21-year-old Murray thought he'd been miserly with his 10 mistakes against No. 31 Melzer.

He was broken when serving for the match at 5-1 and wasted two match points in the subsequent game before finishing off with an ace.

Right now, fourth-seeded Murray isn't Nadal's major concern.

He's got 2007 Australian Open finalist Fernando Gonzalez next. The 28-year-old Chilean rallied from two-sets down and saved match point en route to a 3-6, 3-6, 7-6 (10), 6-2, 12-10 win over Richard Gasquet of France.

Fifth-seeded Jo-Wilfried Tsonga, losing finalist last year, joined fellow Frenchmen Gael Monfils and No. 6 Gilles Simon in the fourth round. He next faces No. 9 James Blake, the second American to reach the final 16 after Andy Roddick.

No. 7 Roddick has a match against Spaniard Tommy Robredo on Sunday night.

Roger Federer's quest for a record-equaling 14th major continues when he plays 20th-seeded Tomas Berdych in an afternoon match on Rod Laver Arena.

Defending champion Novak Djokovic has the closing match on center court.

On the other side of the women's draw, Serena Williams had 6-1, 6-4 win over China's Peng Shuai on Saturday, moving closer to a 10th Grand Slam title.

Williams next faces No. 13 Victoria Azarenka of Belarus, who ousted 2006 Australian Open and Wimbledon champion Amelie Mauresmo.

Olympic gold medalist Elena Dementieva extended her women's winning streak to 13 matches, coming back from 2-5 in the first set to oust Australia's Samantha Stosur.