Former World number one Rafael Nadal reached his first Grand Slam semi-final since 2014 with a superb 6-4 7-6 (9-7) 6-4 victory over Canada's third seed Milos Raonic.
The 14-time Grand Slam winner, who has been troubled by injuries in recent years, saved six set points in the second set before dominating the third.
Nadal, the 2009 champion, faces 15th seed Grigor Dimitrov on Friday after the Bulgarian beat David Goffin.
The Spaniard, 30, remains on course to meet Roger Federer in Sunday's final.
Federer, 35, will play his fellow Swiss Stan Wawrinka in the first semi-final on Thursday.
Nadal is bidding to become the first man in the Open Era - and only the third man in history after Roy Emerson and Rod Laver - to win each of the four Grand Slam titles twice.
The ninth seed's victory means that six of the eight players in the men's and women's semi-finals are over 30.
"I think I am not a very arrogant person so I always have doubts," said Nadal, when asked about whether he thought he might not ever regain his form of old.
"Even when I was winning I had doubts and even more so when I had injuries. But doubts make you work harder.
"I have had a great career but I had some tough moments so that makes me enjoy moments like this even more," he added.
Nadal last reached a Grand Slam semi-final when he won the French Open - his last major title - three years ago.
A succession of injuries raised serious concerns about his future but he has battled back and looked close to his very best against Raonic.
The Spaniard broke the big-serving Canadian once in the first set to take the lead but Raonic, who was the highest seed left in the men's draw, looked like he would level the match in the second.
Raonic needed a medical timeout midway through the set for an unspecified problem, but came back stronger and had three set points on Nadal's serve at 5-4.
Nadal saved them all and then saved two more in the tie-break before Raonic double-faulted on the sixth set point.
The ninth seed took advantage of Raonic's lack of mobility in the third set to wrap up an impressive victory, his 50th since making his debut in the tournament in 2004, with a hold to love.
His win came after two hours and 44 minutes on court and he celebrated with a huge leap before falling to his knees as emotion took over.
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