A round-up of all the men's and women's singles matches from Day 9 at Melbourne Park
Australian Open Day 9: Wozniacki wins but Nadal and Dimitrov are out on day of upsets
Rafael Nadal's drive towards a second Australian Open title came to a shuddering injury-induced halt Wednesday on a day of upsets that saw unseeded Kyle Edmund and Elise Mertens make the semi-finals.
The world No 1 retired against Marin Cilic after an upper right leg problem began troubling him the fourth set on Rod Laver Arena, with the Spaniard wincing in pain and limping as he struggled to continue.
His 3-6, 6-3, 6-7, 6-2, 2-0 exit set up a last-four clash for the former US Open champion against Britain's Edmund, who stunned third seed Grigor Dimitrov 6-4, 3-6, 6-3, 6-4.
Wozniacki gets better of Suarez Navarro
Second seed Caroline Wozniacki withstood a fightback from Spain's unseeded Carla Suarez Navarro to stutter into the semi-finals 6-0, 6-7, 6-2 early Wednesday morning.
"I knew it was going to be tough against her because in the first set a lot of games were very close," said the Dane, who is into a second semi-final at Melbourne Park, after losing her first against China's Li Na back in 2011.
"Another semi-final here, I'm excited," she added after completing a see-saw win in 2hr 11min.
Wozniacki will face another unseeded player, Elise Mertens of Belgium, on Thursday for a place in the final.
"She's had a very good start to the year, she's unbeaten I think," she said of Mertens.
Edmund into his first semi-final
Britain's Kyle Edmund bludgeoned his way past third seed Grigor Dimitrov 6-4, 3-6, 6-3, 6-4 on Rod Laver Arena on Tuesday to reach the semi-finals.
The unseeded 23-year-old, playing in his first grand slam quarter-final, showed no nerves as he blazed away with his fearsome forehand to subdue a nervy Dimitrov.
The Bulgarian struggled to reproduce the form that saw him beat home favourite Nick Kyrgios in the previous round, with his serve especially vulnerable.
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Edmund broke decisively at 4-4 in the opening set with a thunderbolt forehand off a weak second serve.
Dimitrov took the second set but never looked completely comfortable against the ultra aggressive Edmund and a double-fault at 3-4 in the third set proved costly.
The players swapped breaks in the fourth set but Edmund broke again for a 5-4 lead to serve for the match.
A tense final game saw Edmund double-fault but an ace brought up match point and then Dimitrov sliced a backhand long which was confirmed by Hawkeye.
Edmund is the only British man in the main draw after three-times grand slam champion Andy Murray withdrew to have surgery on his hip.
Svitolina blames injury for surprise exit
Ukraine's world No 4 Elina Svitolina said a hip injury was partly to blame for her shock defeat to Elise Mertens in the quarter-finals.
Svitolina's nine-match winning run came to an abrupt end on Rod Laver Arena as Mertens booked her place in the semi-finals with a 6-4, 6-0 win over the fourth seed.
"Today was very tough for me physically," said Svitolina, who was attempting to reach her first grand slam semi-final.
"Going into the tournament, I had a few issues with my health. Yeah, it was very sad that today I was not feeling great.
"It was my hip. I started to feel it actually after the final in Brisbane. Then it was getting worse and then was up and down. You know, I always had the tape, like, a heavy tape under the shorts.
"It's been there all the time. I had pain all the time. But with painkillers, it was fine."
Mertens, the world No 37 and competing in her first Australian Open, was speechless after reaching the last four.
"I'm without words, I don't know what to say. I have mixed emotions, all good emotions," Mertens said.
"I gave it all today, it was a little stressy at the end. I played my game and it went well."
The first Belgian to make the semi-finals in Melbourne since her mentor Kim Clijsters won the title in 2012, Mertens will next meet Caroline Wozniacki or Carla Suarez Navarro.