Coco Gauff of the US consoling Japan's Naomi Osaka at the end of their women's singles match on day five of the Australian Open tennis tournament in Melbourne. Gauff shocked the defending champion 6-3, 6-4 - AFP

MELBOURNE (Reuters): Defending champion Naomi Osaka was knocked out of the Australian Open on Friday, falling 6-3 6-4 in a stunning upset by American teenage sensation Coco Gauff in the third round.

Osaka was the third former Open winner to bow out of the draw after Serena Williams and Caroline Wozniacki, who won the title in 2017 and 2018, lost their respective matches at Melbourne Park earlier in the day. Gauff, who lost to Osaka easily 6-3 6-0 at the US Open last year, avoided a repeat defeat as a string of backhand errors off the Japanese player’s racquet gave the 15-year-old the break midway through the opening set.

The pattern repeated itself in the second set, as Osaka continued to misfire and Gauff served out the victory after just 67 minutes on court.

Barty on a roll, moves into fourth round

Reuters: 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.