Australian Open: Simona Halep overcomes Lauren Davis in marathon match

The big match Saturday had the only two women's major champions left in the tournament playing each other - 2008 Australian victor Maria Sharapova vs. 2016 Melbourne Park champion Angelique Kerber.

Angelique Kerber believes she is reaping the rewards for fighting hard to forget a miserable 2017 after battering Maria Sharapova to reach round four of the Australian Open.

Chung beat fourth-seeded Alexander Zverev 5-7, 7-6 (3), 2-6, 6-3, 6-0 in the third round on Rod Laver Arena.

Photo Sharapova, a former No. 1, is closing in on a top-40 ranking, but she has not gone past the fourth round in the two majors she has played since returning last season from a 15-month suspension for an antidoping violation.

Kerber took the first set in just 29 minutes, displaying her trademark athleticism and forcing Sharapova into a number of erratic shots.

At the height of her crisis of confidence, she went on to crash out against Naomi Osaka in the first round of her US Open title defence.

Born in the same year of the Australian Open's debut at Melbourne Park, Kerber soaked up a birthday serenade from the terraces during her post-match interview on the court.

It will definitely be the only time it happens on the women's side, since these two are the only grand slam, let alone Australian Open, champions left in the draw. She's always risky, especially at the Grand Slams. "This is the matches I'm looking forward to have, especially at the beginning of the year".

Simona Halep survived an almighty scare as American Lauren Davis pushed her all the way in a titanic three-setter which lasted 3 hours and 44 minutes. "I never played the third set so long, so I'm really happy I could stay and win it". I'm still fit. I am still enjoying my tennis. "I think it was a good decision to do it". And it won't have escaped Kerber's attention that she is the last remaining Grand Slam champion in the women's draw.

Also advancing were No. 8 Caroline Garcia and No. 26 Agnieszka Radwanska, who next plays Hsieh.

Kyrgios is now the only Australian with a chance to take an Open singles title.

Another loss at a major had the highly-touted Zverev admitting he may have a problem.

Fifth-seeded Dominic Thiem beat Adrian Mannarino 6-4, 6-2, 7-5 to set up a fourth-round match against Tennys Sandgren, who continued his career-best run by beating Maximilian Marterer 5-7, 6-3, 7-5, 7-6 (5).

Fognini will next play the victor of a later match Saturday between Tomas Berdych and Juan Martin del Potro.

"I have some figuring out to do, what happens to me in deciding moments in Grand Slam", he said. The 2016 victor from Germany and 21st seed roared past the unseeded Russian 2008 champion 6-1, 6-3 in 64 minutes to reach the last 16.