Aus Open PIX: Gauff stuns Osaka; Serena ousted

Images from Day 5 of the Australian Open played at Melbourne Park on Friday.

Gauff ousts defending champion Osaka

With composure that belied her age, Coco Gauff claimed the biggest win of her young career on Friday with a stunning upset of defending champion Naomi Osaka at the Australian Open to reach the fourth round.

The 15-year-old American took advantage of a misfiring Osaka for a brutally efficient 6-3, 6-4 win in just 67 minutes on Rod Laver Arena.

Gauff, who had beaten seven-times Grand Slam champion Venus Williams in her Australian Open debut on Monday, said the win over Osaka ranks "somewhere around the top" of her biggest scalps.

"I thought I played really well today and I was pretty composed and really calm," she told reporters.

After losing to Osaka 6-3, 6-0 at the US Open last year, Gauff said she felt less pressure and more confidence this time around against the Japanese third seed, whose aggressive and heavy groundstrokes had troubled her in their previous meeting.

"She definitely plays faster than most players. I think at the US Open, I wasn't really prepared for that."

"I feel like now I'm more playing, just having fun. And I mean, winning is a cherry on top but I'm honestly having a lot of fun on the court, even in those tight situations," said Gauff.

Gauff, who said she took a break from homework to play her night matches, dazzled the crowd with her poise, holding serve efficiently before a string of backhand errors off Osaka's racket gave the teenager the break midway through the first set.

Osaka appeared to stem the tide after fighting back from a break down early in the second set, but could not keep up the momentum against the steady Gauff.

Gauff won a second break to go up 4-3 amid another flurry of errors from Osaka, before serving out the victory with aplomb.

She next plays either China's Zhang Shuai or American 14th seed Sofia Kenin for a place in the quarter-finals.

Osaka was the third former women's champion to bow out at Melbourne Park on Friday after her immediate predecessors Caroline Wozniacki and Serena Williams lost their respective matches earlier in the day. German Angelique Kerber, who won in 2016, remains in the draw.

Serena's record bid foiled by Chinese battler Wang

Serena Williams suffered her earliest exit from the Australian Open in 14 years on Friday, falling to China's Wang Qiang in a stunning third round reversal that left her bid for a record-equalling 24th Grand Slam title in tatters once again.

Having conceded one game to Wang in a US Open trouncing four months ago, Williams staggered to an error-strewn 6-4, 6-7(2), 7-5 defeat at Rod Laver Arena that sent shockwaves through Melbourne Park and tore open the women's draw.

It was the American's earliest exit from the year's first Grand Slam since her 2006 title defence was ended by Daniela Hantuchova. Doubts about her hopes of matching Margaret Court's Grand Slam haul have resurfaced.

Williams has recovered from her share of Grand Slam setbacks, but this one left an especially bitter taste.

"It's all on my shoulders," the 38-year-old said ruefully.

"I just have to pretend like I don't want to punch the wall, but in reality I do."

A day before Chinese celebrate the Lunar New Year, 27th seed Wang played the match of her life, soaking up huge pressure to land the biggest scalp of her career.

She wavered at times and was broken when serving for the match at 5-4 in the second set.

Wang squandered two match points in the nerve-shredding finish, and ultimately was relieved when Williams surrendered by firing into the net, her 56th unforced error.

Last year, China's top-ranked player knocked world number one Ash Barty out of the US Open fourth round, a few months after mourning the death of her longtime coach Peter McNamara.

"I think he could see me playing today. He will be proud of me," the 28-year-old told reporters.

Wang said she would eschew traditional Chinese New Year celebrations before preparing for her fourth round clash against Tunisia's Ons Jabeur, another giantkilling rival on a surprising run at Melbourne Park.

Jabeur knocked out Williams' good friend and former world number one Caroline Wozniacki, drawing the curtain on the retiring Dane's career in tennis.

No matter what happens, Wang may savour her triumph against Williams for a life-time.

She stayed patient as the American dug in stubbornly in the decider and saved a string of break points with her formidable serve.

As Williams' shrieking increased, Wang nosed ahead to 6-5 after firing a blistering backhand that clipped the line.

She thought she had blown her chance with unforced errors on two match points but it was Williams who was left bowing her head after failing to clear the net.

Barty on a roll, moves into fourth round

World number one Ash Barty produced a clinical masterclass of ball striking and placement to beat Elena Rybakina 6-3, 6-2 on Friday and advance to the Australian Open fourth round.

With numerous fans wearing bright pink "Barty Party" t-shirts in the stands of Rod Laver Arena supporting her, the 23-year-old Barty had relatively little trouble against the 20-year-old from Kazakhstan.

Neither was able to hold serve in the opening four games of the third-round clash but once Barty held in the fifth game of the first set it was virtually one-way traffic from then on.

The Australian clinched the first set in 32 minutes and while Rybakina put pressure on her serve twice in the second set, Barty managed to win the critical points and advanced to a fourth-round clash with either Alison Riske or Julia Goerges.

Tunusia’s Jabeur sends Wozniacki packing

A tearful but happy Caroline Wozniacki headed into retirement on Friday after a 7-5, 3-6, 7-5 third-round defeat at the hands of Tunisia's Ons Jabeur ended her participation in the Australian Open and her 16-year career.

The 29-year-old said last year that Melbourne Park, where she won her lone Grand Slam title two years ago, would be the site of her final outing as a tennis professional.

Wozniacki, one of the most popular players on the women's circuit, sat beside the court soaking up the atmosphere for a few moments before addressing a packed Melbourne Arena.

"I'd like to thank the fans, the support we feel on court is really amazing. Also the support I've had my from family, and especially my dad, who has coached me all those years," she said, smiling through the tears.

"I usually don't cry, sorry, those are the special moments I'll remember. It's been really amazing, a great ride. I really am happy, though, I'm ready for the next chapter."

Wozniacki was renowned for having one of the best defences in the women's game but Jabeur ushered her out of the door with a barrage of 43 winners.

The Dane showed the fighting spirit of a champion to battle back from 3-0 down in the deciding set but Jabeur always looked to have the measure of her service when she was able to keep her big shots within the lines.

Wozniacki lost her final service game as a tennis professional and her last stroke was a forehand that went long to send the Tunisian world number 78 into the fourth round of a Grand Slam for the first time.

"I think it was only fitting that my career would end with a three-setter, a grinder," Wozniacki laughed.

"And that I would finish my career with a forehand error, these are the things I have been working for all of my career."

With the entire crowd on its feet applauding, Wozniacki completed her final afternoon on court by performing a lap of honour draped in the Danish flag.

Jabeur, who beat 12th seed Johanna Konta in the first round and former world number four Caroline Garcia in the second, will next face the winner of the match between Serena Williams and Wang Qiang.

"I'm really happy, usually I lose in the first round at this Grand Slam," said the 25-year-old.

"I don't have much experience so I had some nerves, especially in the third set.

"I'm really lucky that I played you Caro," she added, turning to Wozniacki.

"You have been such an inspiration."