Tsitsipas survives thriller as seeds keep tumbling in Melbourne

Third seed Stefanos Tsitsipas avoided becoming another shock casualty in a tournament of upsets at the Australian Open on Sunday, surviving via a thrilling 6-4 6-4 3-6 4-6 6-3 win over Italian Jannik Sinner to keep his dreams of a maiden Grand Slam title alive.

This after Top seed Iga Swiatek was bundled in fourth round early on Sunday, with title threat Coco Gauff also exiting in tears, as a pair of underestimated Grand Slam champions tore open the women's draw.

“It was a long match. I feel like I've spent a century on this court,” Tsitsipas said of the contest, which lasted just over four hours. “It was a ripper, as they say here. I can feel my face burning from the effort today.”

World number one Swiatek was sent packing by Elena Rybakina in the early match at Rod Laver Arena, the Pole falling 6-4 6-4 to the Kazak Wimbledon winner who started her tournament in the Melbourne Park wilderness of Court 13.

The result means this year's Australian Open will be the first Grand Slam tournament in the open era where the top two seeds in both the men's and women's singles draws have lost before the quarterfinals.

Rybakina, the 22nd seed, might have expected to face Gauff in the quarterfinals but the much-hyped American teenager was upset 7-5 6-3 by Jelena Ostapenko, the forgotten Grand Slam winner of women's tennis.

The 2017 French Open champion thrashed 30 winners past Gauff on Margaret Court Arena, her last two sealing the match in style to leave the 18-year-old in tears at her post-match media conference.

At a tournament fast running out of star power, unheralded Czech Jiri Lehecka landed another blow for the lesser lights as he toppled Canadian sixth seed Felix Auger-Aliassime 4-6 6-3 7-6(2) 7-6(3) in the men's tournament.

The 21-year-old plays Tsitsipas next, seeking revenge for a loss to the Greek in the Rotterdam semifinals last year.

“He'll know what my strengths are. He'll feel I can get him under pressure,” Lehecka said.

While Lehecka was a bolt from the blue, big things have been expected of Sebastian Korda for some time and the young American is finally delivering on expectations at Melbourne Park.

He took another step towards emulating his Australian Open-winning father Petr by booking his first Grand Slam quarterfinal with a 3-6 6-3 6-2 1-6 7-6 (10-7) win over Hubert Hurkacz at Rod Laver Arena.

Korda, whose father won the 1998 title under the Czech flag, showed impressive composure as Polish 10th seed Hurkacz roared back to level the fifth set tiebreak at 7-7 by winning four consecutive points.

Korda held firm, closing it out with a backhand winner to set up a clash with Russian 18th seed Karen Khachanov.

While the high seeds have tumbled, American Jessica Pegula has been rock solid and reached her third consecutive quarterfinal at Melbourne Park by beating Czech 20th seed Barbora Krejcikova 7-5 6-2.

Third seed Pegula will face 24th-seeded twice champion Victoria Azarenka, who fought back from a set down to beat Zhu Lin 4-6 6-1 6-4 and end the Chinese star's impressive run.

Zhu, who beat sixth seed Maria Sakkari in the last round, started well and broke the 2012 and 2013 champion in the opening game before allowing her back, only to pull away from 3-3.

With the first set in the bag, world number 87 Zhu then came under pressure and Azarenka took the second set 6-1.

The Belarusian broke at 4-4 in the decider before showing composure to defend two break points and serve out for the win.