Australian Open: Nadal out, Wozniacki survives scare to reach semis

An injured and visibly struggling Rafael Nadal retired while trailing in the fifth set of his Australian Open quarter-final match against Marin Cilic on Tuesday.

The top-ranked Nadal saved five break points in the last game before Cilic broke his serve, then went to shake hands with the umpire and his opponent.

The No. 6-seeded Cilic advanced with a score of 3-6, 6-3, 6-7 (5), 6-2, 2-0, retired .

Cilic will play a semifinal against No. 49-ranked Kyle Edmund, who earlier beat Grigor Dimitrov in four sets.

It was only the second time Nadal had retired during a Grand Slam match — the last time was also an Australian Open quarter-final, in 2010 against Andy Murray.

On Tuesday night, he needed a medical timeout after going down 4-1 in the fourth set, getting treatment on his upper right leg and hip. He returned but was clearly bothered by the injury, limping and trying to stretch between points.

Nadal had a delayed start to the season because of an injured right knee, but appeared to be in good form through the first four rounds. Now the 16-time major winner hasn't won back-to-back Australian Open quarter-finals since 2008 and `09, the year he won his only title at Melbourne Park.

His absence also means there's only one of last year's finalists remaining in the tournament. Roger Federer, who beat Nadal in five sets last year, is playing Tomas Berdych in a quarter-final on Wednesday.

Serena Williams didn't defend her title, deciding she hadn't had enough time to prepare following the birth of her first child last September. Her older sister, Venus Williams, was beaten in the first round.

On top of that, six-time champion Novak Djokovic was upset in the fourth round on Monday by Hyeon Chung.

Wozniacki survives scare

Caroline Wozniacki has advanced to the semifinals at Melbourne Park with a 6-0, 6-7 (3), 6-2 win over Carla Suarez Navarro in an early Wednesday morning finish at Rod Laver Arena.

The second-seeded Wozniacki won the first seven games of the match but trailed 4-2 in the second set before staging a comeback. Suarez Navarro had to save one match point in the 10th game before Wozniacki was outclassed in the tiebreaker.

Wozniacki had an early break in the deciding set to take a 4-2 lead, then broke again in the seventh game before serving out the match in 2 hours, 11 minutes.

Wozniacki, who can return to the No. 1 ranking with her first Grand Slam singles title, plays Elise Mertens in the semifinals.

Edmund shocks Dimitrov

There'll be a British man in the Australian Open semifinals for the seventh time in nine years. It'll be Kyle Edmund this time, though, not Andy Murray.

Edmund upset No. 3-ranked Grigor Dimitrov 6-4, 3-6, 6-3, 6-4 on Tuesday to reach a Grand Slam semifinal for the first time. Edmund had never played in a major quarter-final, had never won five consecutive matches at tour level, had lost both of his previous matches against Dimitrov and had never beaten a top five player.

"I am loving it right now, just the way I'm playing," Edmund said. "My first Grand Slam semifinal. First time I played on one of the biggest courts in the world. To beat a quality of player like Grigor. They're great feelings. So, yeah, I just try to enjoy it as much as possible."

After breaking Dimitrov's serve in the ninth game of the fourth set, Edmund set up match point with an ace. Then he had to wait before a video challenge confirmed that Dimitrov's last shot — a floating backhand — was out.

"I just held my nerve in that last game and prayed that last ball would be out," Edmund said. It was out. And so was Dimitrov, who lost a five-set semifinal here last year to Nadal and had only just beaten Edmund two weeks ago at the Brisbane International.

"When you're on these types of stages, reaching the last stages of the best tournaments in the world, it's very pleasing. But of course I want to keep going," Edmund said.

Dimitrov, who won the season-ending ATP Finals last November, was coming off back-to-back wins over No. 30 Andrey Rublev and Nick Kyrgios, who was the last Aussie still in contention in the tournament.

"There's no point for me to say what I did wrong — it's all about him right now," Dimitrov said, referring to Edmund. "Everything went his way today. It's hard to hide a disappointment. It hurts, and so it should."

Dabrowski splits doubles matches

Canada's Gabriela Dabrowski and her women's doubles teammate Xu Yifan of China were eliminated in the quarter-finals of their tournament.

Dabrowski and Xu fell 0-6, 6-1, 7-6 (2) to Russia's Ekaterina Makarova and Elena Vesnina.

The Canadian, though, did advance in mixed doubles, winning her round of 16 match with Croatian teammate Mate Pavic in straight sets.

Mertens continues surprising run

Mertens is the centre of attention in Belgium after reaching the semifinals in her debut at the Australian Open.

Mertens upset fourth-seeded Elina Svitolina 6-4, 6-0 to extend her winning streak to 10 matches, and became the first Belgian since Kim Clijsters in 2012 to reach the semifinals here.

"If you believe in yourself, then anything can happen," she said. "But of course semis is, `Wow."'

Mertens, who trains at Clijsters's academy, added: "Kim, thanks for watching. "I'm trying to be in your footsteps this week."

Coming off a successful title defence at the Hobart International, Mertens dominated against Svitolina, who had also been on a nine-match winning roll after winning the Brisbane International.

Svitolina had won their only previous tour-level match, but had no answers on Rod Laver Arena and later said hip trouble had been bothering her all year.

The 22-year-old Mertens was one of the biggest movers on the women's tour in 2017, improving her year-end ranking from 120 to 35 and won her first career title.