MELBOURNE (Reuters) - Rafa Nadal's Australian Open run ended abruptly in the quarter-finals on Tuesday when injury forced the top seed to retire in the fifth set against Croatia's Marin Cilic.
The Spanish world number one struggled with a muscle strain in his thigh from late in the fourth set before abandoning the match at 3-6 6-3 6-7(5) 6-2 2-0, retiring for only the second time in more than 250 grand slam matches.
Nadal's only other retirement at a grand slam came in the 2010 quarter-finals in Melbourne against Andy Murray and the world number one complained that too many players getting injured.
"Somebody who is running the tour should think a little bit about what's going on," he said. "Not for now that we are playing, but there is life after tennis.
"I don't know if we keep playing in these very, very hard surfaces what's going to happen in the future with our lives."
Cilic's victory sent him through to his second Australian Open semi-final in eight years, where the Croatian sixth seed will face 49th-ranked Briton Kyle Edmund.
Edmund bludgeoned his way to a shock 6-4 3-6 6-3 6-4 victory over third seed Grigor Dimitrov, showing no nerves in his first grand slam quarter-final as he blazed away with his fearsome forehand.
In the women's draw, Belgian Elise Mertens pulled off a huge upset by trouncing fourth seed Elina Svitolina in straight sets.
The 22-year-old became the first Belgian woman to make the semi-finals in Melbourne since her mentor Kim Clijsters in 2012, and will meet second seed Caroline Wozniacki of Denmark in the semis.
Former world number one Wozniacki made a strong start against Carla Suarez Navarro in the day's last match, but the Spaniard fought back, taking a second set tiebreak before Wozniacki recovered with strong baseline tennis to win 6-0 6-7(3) 6-2.
Highlights of Tuesday's ninth day of the Australian Open, the first grand slam tournament of the year (times in GMT):
1440 WOZNIACKI POWERS PAST SUAREZ NAVARRO
Second seed Caroline Wozniacki of Denmark powered past Spain's Carla Suarez Navarro 6-0 6-7(3) 6-2 to reach the quarter-finals.
Wozniacki takes on unseeded Belgian Elise Mertens in the semi-finals.
1310 DISAPPOINTED NADAL SET FOR INJURY SCAN
Top seed Rafa Nadal will have a scan on Wednesday to determine the nature of the injury that caused him to retire against Marin Cilic in the quarter-finals.
"We need to wait a couple of hours. Tomorrow I am going to do a test, an MRI here, then we will know," he said. "I start to feel the muscle little bit tired in the third, but playing normal, no limits, no limitation.
"Then in the fourth at one movement, one drop shot I think, I felt something. At that moment I thought something happened, but I didn't realise how bad."
1200 NADAL RETIRES HURT, CILIC REACHES SEMI-FINALS
Injury cut short world number one Nadal's progress at the Australian Open with the Spaniard retiring in his quarter-final against Cilic after going a break down in the deciding set.
Sixth-seed Cilic's 3-6 6-3 6-7(5) 6-2 2-0 victory sent him through to the semi-finals where he will face Briton Kyle Edmund.
0655 EDMUND REFLECTS ON SHOCK WIN
Kyle Edmund continues to fly solo in the absence of injured former world number one Andy Murray after he became the sixth British man in the Open Era to reach a grand slam semi-final.
"Now I know what it feels like to be Andy Murray for the last eight years. The better you do the more attention you get," the 23-year-old said after his four-set victory over Grigor Dimitrov.
"It's probably the first time I have done well on my own... It's a good problem to have when you're winning."
Three-times grand slam winner Murray was well aware of his compatriot's achievement, exclaiming "Wow! @kyle8edmund" on Twitter after the quarter-final.
0638 EDMUND OUSTS DIMITROV
Unseeded Briton Kyle Edmund reached the semi-finals of a grand slam for the first time with a 6-4 3-6 6-3 6-4 win over Bulgarian world number three Grigor Dimitrov.
The 23-year-old, ranked 49th in the world, next faces Croatian Marin Cilic.
0345 MERTENS' MESSAGE TO IDOL CLIJSTERS
Mertens becomes the first Belgian woman since Kim Clijsters in 2012 to reach the last four at Melbourne Park.
"Hello Kim, thanks for watching. I know you sent me a message before the match. Don't be too stressy! She said she had so much stress in my last match. I am trying to be in your footsteps this week," Mertens said after beating Svitolina.
0327 HIGH-FLYING MERTENS TOPPLES SVITOLINA
Belgian world number 37 Elise Mertens continued her superb start to the season with a surprise 6-4 6-0 win over fourth-seeded Ukrainian Elina Svitolina in the quarter-finals.
The 22-year-old, who won a warmup event in Hobart prior to the Australian Open, will take on second-seed Caroline Wozniacki in her first grand slam semi-final.
0045 PLAY UNDERWAY WITH DOUBLES ENCOUNTER
Play got underway on schedule at 11 a.m. local time (0000 GMT) at Melbourne Park with doubles matches on both the main showcourts. Hisense Arena has seen its last action this year.
The temperature was 21 degrees Celsius (69 degrees Fahrenheit) and forecast to reach a high of 24. Read our preview of the day's action here:
(Compiled by Nick Mulvenney, Aditi Prakash and Simon Jennings,; Editing by Ed Osmond)
