Australian Open: Garbine Muguruza and Stan Wawrinka advance, Dominic Thiem's mother a step closer to new tattoo

Unseeded former world No 1 Muguruza beat Kiki Bertens, former champion Wawrinka overcomes Medvedev, Thiem says his mum will get a kangaroo tattoo if he goes all the way in Melbourne

Garbine Muguruza of Spain in action against Kiki Bertens of the Netherlands during a fourth round match on day eight of the Australian Open. EPA

Two-time Grand Slam champion Garbine Muguruza underlined her return to form as she beat ninth seed Kiki Bertens in 68 minutes to reach the Australian Open quarter-finals on Monday.

The unseeded former world No 1 won 6-3, 6-3 on Rod Laver Arena and faces German 17th seed Angelique Kerber or 30th seed Anastasia Pavlyuchenkova of Russia in the last eight.

Just three of the top 10 seeds remain - top seed Ashleigh Barty and seventh seed Petra Kvitova meet in the quarter-finals.

The other is Simona Halep, the fourth seed, who plays Estonian 28th seed Anett Kontaveit.

Muguruza, 26, reunited with Conchita Martinez, her fellow Spaniard and the 1994 Wimbledon champion, at the start of the year in the hope of reviving her failing career.

Muguruza, who has suffered a barren 18 months, said she was enjoying having Martinez on her coaching team.

"When you talk to another player you don't have to put too many words, you right away understand each other," she said.

As part of her reboot, Muguruza spent a few days in the off-season climbing Mount Kilimanjaro to clear her mind of tennis.

Muguruza ended 2019 ranked 36 in the world, the first time since 2014 that she had finished the year outside the top 20.

But she has flickered back to life in 2020, reaching the semi-finals in Shenzhen at the start of the year before pulling out of Hobart in the quarter-finals with a virus.

"First day I was not feeling good at all [in Melbourne] but every day it's improving," she said.

Muguruza emphatically won the first set in 30 minutes against a shell-shocked Bertens.

She took the momentum into the second set, breaking for a quick 1-0 lead, only to be broken back immediately.

The resurgent Spaniard broke Bertens once more for 3-2 and comfortably held for 4-2.

Muguruza broke again for a 5-3 lead and put Bertens under pressure with some powerful groundstrokes from the back of the court.

She failed to put Bertens away on the first match point but sealed the win with another big forehand, this one pinging down the line.

Wawrinka rallies to take down Medvedev

Former champion Stan Wawrinka battled past Russian fourth seed Daniil Medvedev in five sets to reach the Australian Open quarter-finals with a 6-2, 2-6, 4-6, 7-6, 6-2 victory.

Medvedev came into the contest having won both their career meetings at Grand Slams in four sets but the 2014 Australian Open champion took the opening set with a double break of the Russian's serve.

Medvedev, who lost to Rafa Nadal in five sets in last year's US Open final, levelled the contest by breaking Wawrinka twice in the second and nosed ahead in the match with a break in the seventh game of the third.

But Wawrinka refused to yield and took the fourth set tiebreaker comfortably before breaking Medvedev twice in the fifth to set up a quarter-final against either German seventh seed Alexander Zverev or 17th seed Andrey Rublev of Russia.

Thiem edges closer to his mum getting a kangaroo tattoo

Dominic Thiem edged closer to his mum getting a kangaroo tattoo after the world No 5 swatted aside an error-prone and underarm-serving Gael Monfils to book a maiden Australian Open quarter-final.

The two-time Roland Garros finalist proved too wily for his experienced French opponent, crushing him 6-2, 6-4, 6-4 on Rod Laver Arena.

It set up a last-eight showdown with either world No 1 Rafael Nadal or temperamental Australian Nick Kyrgios, who play later.

Thiem revealed that he made a pact with his mother Karin last year that each time he won a title she would get a tattoo to mark the occasion.

"After a pretty bad start to the season last year after some losses she said after a long trip to Indian Wells from Rio, all really jet-lagged, that if I won that she would get a tattoo," the Austrian said.

"I ended up winning that one so this tradition started."

She has since got tattoos of an eagle feather to mark winning in the United States and a panda after he claimed a title in China.

Asked what she would be marked with if he clinches the Australian Open, he replied: "For sure a kangaroo."