MELBOURNE, Australia — Ana Ivanovic's hopes of a return trip to the Australian Open final fell apart in a barrage of mistakes Friday as Russia's Alisa Kleybanova ousted the 2008 runner-up with a 7-5, 6-7 (5), 6-2 victory in the third round.

With the 19-year-old Kleybanova constantly aggressive, fifth-ranked Ivanovic lost her serve nine times and finished with 50 unforced errors to just 23 winners.

When it was over, Kleybanova dropped to the ground on both knees, pumped her fists and blew kisses to the crowd. Ivanovic appeared to be nearly in tears as she walked off court, throwing a towel to someone in the crowd.

The Serb's loss came on a day that the late match between second-ranked Roger Federer and former No. 1 Marat Safin — which the Swiss star won in three sets — was supposed to produce the biggest news.

Instead, ethnic violence erupted between nationalist fans after Serbia's Novak Djokovic, the defending men's champion, beat Bosnian-born American Amer Delic.

One of several thrown chairs hit a woman and left her briefly unconscious. Insults and water bottles filled the air. Arrests were made, with dozens of people ejected from Melbourne Park.

This was what organizers had feared when they announced before the tournament that they were instituting a no-tolerance policy for disruptions.

They wanted the focus to remain on tennis — such as Kleybanova's upset victory, Andy Roddick's 22 aces while winning in straight sets or top-ranked Jelena Jankovic and No. 3 Dinara Safina advancing.

Instead of talking about how defending champion Djokovic reached the third round with a 6-2, 4-6, 6-3, 7-6 (4) victory packed with drama and good sportsmanship, the 21-year-old Serb and Delic were mostly quizzed about the chaotic scene that followed — when their supporters clashed outside near a big-screen TV showing the match.

Police said about 30 Bosnian and Serbian youths were ejected from Melbourne Park. Two men were charged with riotous behavior and a third was fined on the spot. The woman who was knocked out was not seriously injured.

"There's absolutely no place for that here. This is a tennis match," said Delic, who attended the University of Illinois and lives in Jacksonville, Florida. "As I'm sure you all saw at the end, Novak and I are friends. We're both competitors. In the end it was a fair match, and there was no reason for such things."

Before finally asking reporters to change the subject, Djokovic lamented that players can't control their fans. Delic had earlier used his Web site to ask his backers, who were boisterous to the point of disruption in the qualifier's first two matches, to tone it down.

And that wasn't even all of the day's drama — a man was arrested after dancing across a court, naked from the waist down, as Serena and Venus Williams won a second-round doubles match.

In a rematch of the 2005 men's semifinal, won by Safin en route to the championship, was dominated by Federer, who again looked sharp in his pursuit of a 14th Grand Slam title that would tie Pete Sampras' record, winning 6-3, 6-2, 7-6 (5).

Federer never faced a breakpoint, and the mercurial Safin's growing frustration nearly boiled over when he was called for a foot-fault on his second serve. That gave him a double-fault and Federer a 4-1 lead in the third-set tiebreaker. Safin rallied to lead 5-4 before Federer ran off the last three points, the last on a backhand winner down the line.

"He gave me quite a few free points in the first two sets, but after that he got tougher," Federer said. "I'm pretty lucky I got through in three."

Safin has said he is unlikely to continue playing after this year. Federer clearly would miss him.

"I always like to play Marat," Federer said. "We go back, we like playing each other. It doesn't matter who wins."

After dropping the first set, the 21-year-old Ivanovic lost her first two service games in the second, falling behind 0-3. She rallied to force a tiebreaker, where both women were pumping their fists after every point they won. Ivanovic did a three-punch combination after whacking an overhead winner on set point.

The jubilation was short-lived: Ivanovic found herself again down 0-3 in the deciding set and never caught up. Serving at 2-5, she fell behind 0-40. She saved one match point with a high, lunging volley winner before Kleybanova hit a forehand crosscourt that went untouched to end the match in 2 hours and 43 minutes.

Kleybanova, who reached the fourth round at Wimbledon last year in her third Grand Slam, dropped to her knees in relief and disbelief.

Unlike their fans, there was no animosity on court between Djokovic and Delic.

"Of course, I have a big respect for Amer," Djokovic said, to loud cheers from the crowd. "He absolutely deserves your applause and even more. He has one of the biggest serves on tour. It was very difficult for me to read."

Djokovic next plays the winner of a late match between American Mardy Fish and 2006 runner-up Marcos Baghdatis of Cyprus.

Roddick had a 6-3, 6-4, 6-2 win over Fabrice Santoro and next plays No. 21 Tommy Robredo of Spain, who beat Taiwanese player Yen-hsun Lu.

"It was one of the most exciting matches of my life," Kleybanova said. "I will never forget this night."

No. 8 Juan Martin del Potro of Argentina, who won a warmup tournament in New Zealand, extended his winning streak to seven matches. No. 19 Marin Cilic of Croatia ousted No. 11 David Ferrer of Spain.

On the women's side, Olympic silver medalist Safina beat No. 25 Kaia Kanepi of Estonia. Fellow Russians Vera Zvonareva, seeded seventh, and No. 10 Nadia Petrova also advanced to the fourth round.

Unseeded Jelena Dokic, a former Wimbledon semifinalist making her first appearance in the main draw of a Grand Slam after a three-year absence to deal with personal problems, knocked off a seeded player for the second straight round, rallying from a set down to beat No. 11 Caroline Wozniacki of Denmark.