It's one of the first times it's happened to me.
"I do believe since the roof is on that there is no air circulation in the stadium".
Federer was said by ESPN to be in some physical distress immediately after the match as he struggled to control his breathing, although he was able to fulfil his media duties not long after. You try to play. I think just that makes it a totally different US Open. "Today he definitely was not at his best, but I'll take it".
However, there also seems to be another factor as to why Federer failed to reach the quarter-final, and he's discussed it in his post-match presser.
Still, Millman is 18-15 this season, and there's little question he'll play more matches this year than any other in his professional career.
Said Millman: "Obviously it's probably a bit of a shock to a lot of people [that I won]".
He reached the quarterfinals for an 11th consecutive appearance in NY as he bids for a third U.S. Open championship and 14th Grand Slam trophy.
Errors flowed from the 37-year-old's racquet, 76 unforced ones to be precise - although that doesn't even tell the full story of the weird tactics he was employing, losing faith in his groundstrokes and offering up a limp set of drop-shots that allowed Millman to assume complete control.
"The matches I've played against him (Federer) have shaped me into the player that I am today", said Djokovic, who beat the Swiss at the Cincinnati final in the lead up to the U.S. Open.
Heat, age and a relentless John Millman combined in a ideal storm to drive Roger Federer to the US Open exit on Monday, leaving the victor of a record 20 Grand Slam titles looking every bit the 37 year old he is. "But why not? I think it's a disservice to who I am if I go out there and don't have that belief".
Monday's defeat followed Federer's surprise quarter-final exit at Wimbledon where he lost 2-6, 6-7 (5/7), 7-5, 6-4, 13-11 to South Africa's Kevin Anderson in a tie where he had a match point.
"I love his intensity", Federer said of Millman, his summer hitting partner in Switzerland earlier this year.
Second seed Federer, who had not dropped a set in his first three matches, was uncharacteristically sloppy, committing 77 unforced errors and 10 double faults while landing just 49 percent of his first serves.
Things grew tougher in the second as a sluggish Djokovic laboured before again clinching the set with a break.
Suarez Navarro, who was also a quarter-finalist in NY in 2013, goes on to face American 14th seed Madison Keys, the runner-up in 2017.