Millman received a standing ovation as he left Arthur Ashe Stadium, and rightly so - the last time a male Australian tennis player reached a quarter-final at Flushing Meadows was Lleyton Hewitt 12 years ago at the 2006 Open.
The No. 21-seeded Nishikori continued his strong season after returning from a wrist injury that forced him to miss the US Open a year ago.
"I was really tested", Djokovic said on court after the match. "It's easier said than done, especially in these kind of conditions".
Suarez celebrated her 30th birthday with a victory over five-time Grand Slam victor Maria Sharapova on Monday. "This has been definitely the toughest US Open in the last 10 years that I have played in in terms of conditions". I have lost - probably the biggest match I lost against him was here back in 2014, I think, in semis. Instead, Cilic held and then broke Nishikori on his way to evening the set at 4-all; but then Nishikori took the final two games. This will be Keys' second consecutive semifinal appearance at the US Open.
"There was always part of me that believed I could come back relatively quickly to the level of tennis that I once was playing", sixth seed Djokovic told reporters after he completed a 6-3 6-4 6-2 semi-final demolition of Japan's Kei Nishikori.
The 20-year-old Osaka said she was nervous, claiming to be "freaking out inside" - though it certainly never showed.
But after laboring through the heat in her previous match, Tsurenko said she was sick Wednesday, waking up with a sore throat and not breathing well. "He made me run and he made me earn my match today".
The No. 6-seeded Djokovic, who won Wimbledon in July, had been drawn to face Federer with a semifinal berth at stake. She needed just 26 minutes to win the first set and finished the match in just under an hour.More news: Ex-Trump campaign aide jailed in Russian Federation probe
It was another hot afternoon Wednesday, with temperatures in the 30s C, but feeling much hotter due to the humidity.
Keys has made it this far in a major for the fourth time in her career.
"But at the same time, I felt like the six months off served me very well to find new motivation, inspiration, to recharge my batteries".
It was one of the odder scenes in a night filled with weird sequences, but it was also one of the best U.S. Open moments so far.
Things started well for the two-time victor as he raced into a 3-0 lead, and despite Millman's best efforts he could not claw the break back as the Serb remained comfortable on serve. I hope you die slowly, but f***ing painfully.You have deserved it! She has 23 Grand Slams to her name and is just one Grand Slam away from equalling the world record set by Margaret Court (24).
July's Wimbledon champion had been drawn to face Federer with a semifinal berth at stake. Djokovic was only too happy to have a break.
John Millman, rear, exits to change his shoes he said were soaked from sweat, while opponent Novak Djokovic changes his shirt on court.