This is a rematch of the French Open final, won by Nadal in June.
"I'm going to remember this match, for sure". But there has to be one.
"On clay, I think it's one of the biggest challenges in sports to beat this guy or to compete with this guy", said Thiem, who is in the US Open quarterfinals for the first time in four tries. He saved 12 break points, including three while serving at 5-5, 0-40 in the fifth set.
At this point, Thiem had to ask for a new pair of shoes and socks because his were waterlogged from sweating so much.
"After that first set", Nadal said, "the match became more normal". But he is still a rarity in the tennis circles, in that he has beaten Nadal twice on clay: in Madrid past year and Rome this time around.
Thiem broke three times in a 24-minute first set on Tuesday, handing Nadal just his third "bagel" at a Grand Slam.
With his first words to the media, Thiem underscored the weight of this match to both men. That mistake might have stayed in Nadal's head, because he played terribly in the ensuing tiebreaker. The 32-year-old Spaniard, a 17-time Grand Slam champion, knows better than anyone how to will a way out. He pulled off some stunners but also had to account for 58 unforced errors in the end.
The conclusion to the near five-hour quarter-final, which ended after 2am local time, came in a tie-break.
"It's been a great battle", an exhausted Nadal said.
"To be honest, I am very, very sorry for Dominic", he added. A tough match against a great opponent. He weathered the early storm, stepped further back into the court - nearly near the backstop - and set about solving the Thiem puzzle.
Nadal trailed by a break in the third set before taking it.
"The conditions have been tough out there, too".
"I am the guy to look at myself".
"I'm sad for him because when this moment arrived, he did all the things well to win the match".
'I think from the third set he moved a little bit up. "I hope that we have many more in the future with a different end". Defending champion Stephens is up first on Arthur Ashe Stadium, facing No. 19 seed Anastasija Sevastova in a rematch of Stephens' three-set victory in the same round at Flushing Meadows a year ago.
"It's good to have now two days that probably give me the chance to be on my 100 per cent in the semi-finals".
For the second night in a row, the end of The Tennis Podcast had to be recorded at past 2am in NY in order to cover the thrilling events of the US Open night session.
But while Isner was playing before what could count as a home crowd, del Potro got all manner of support throughout, from the blue-and-white flags or soccer jerseys dotting the stands to the repeated singsong chants of his nickname, "Delpo", punctuated by clapping.