Russian qualifier Aslan Karatsev extended his extraordinary Australian Open run to the semi-finals on Tuesday, as Japan's Naomi Osaka underlined her title credentials with an emphatic win.
Karatsev, the world number 114, beat a hobbling Grigor Dimitrov 2-6, 6-4, 6-1, 6-2 to become the first man to reach a Grand Slam semi-final on debut.
The 27-year-old has now knocked out three seeds on his run to the last four, where he will face world number one Novak Djokovic or US Open finalist Alexander Zverev.
"It's an unbelievable feeling," said Karatsev, whose career so far has been badly compromised by injury.
"It was tough at the beginning for me to hold my nerves, but I tried to find a way to play."
Karatsev becomes only the second qualifier to reach the Australian Open semi-finals after Bob Giltinan in 1977.
He is also the lowest-ranked man, at 114, to make the semis at a Slam since Goran Ivanisevic at Wimbledon in 2001 when ranked 125.
After a five-setter with Felix Auger-Aliassime in round four, Karatsev had an easier ride against Dimitrov who was wincing with pain from the third set.
The Bulgarian 18th seed, who was barely able to serve, took a medical timeout after the third set but his movement was always hampered and he limped off the court after Karatsev's win.
- 'I couldn't be lazy' -
It was a very different story on the women's side as three-time major winner Osaka showed her superiority to reach her fourth Grand Slam semi-final with a 6-2, 6-2 win over Taiwan's Hsieh Su-wei.
Displaying great focus against the awkward Hsieh, ranked 71 and playing her first Slam quarter-final aged 35, Osaka hit 24 winners and was detained on Rod Laver Arena for only 66 minutes.
"I told myself just to be really intense from the beginning," said the Japanese star, the reigning US Open champion.
"I felt like I knew what to expect and that I couldn't afford to be lazy with my footwork or anything.
"I didn't want to play three sets today."
Later, eight-time champion Djokovic will test his powers of recovery against Zverev, while old enemies Serena Williams and Simona Halep also go toe-to-toe.
Djokovic has not practised between matches since injuring his abdomen during a five-set win against Taylor Fritz on Friday and was made to work hard on Sunday by Milos Raonic, dropping another set, before reaching the quarter-finals for the 12th time.
Last year's winner showed fewer signs of pain against Raonic, but still grimaced after stretching for some shots and admitted afterwards he was risking an extended period on the sidelines by playing on.
"I mean, it's kind of a gamble, that's what the medical team told me," said Djokovic, who is chasing an 18th Grand Slam trophy in Melbourne.
Djokovic beat sixth seed Zverev in a match that went the distance in the ATP Cup the week before the Australian Open.
"We played an exhausting match in the ATP Cup and I won't expect anything less," said the Serb, who has a 5-2 win-loss record against the German world number seven.
In the second women's quarter-final, world number two Halep said she wanted to replicate the "best day of my life" -- when she beat Williams 6-2, 6-2 in the 2019 Wimbledon final.
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