Facing his semi-final against Argentine Juan Martin del Potro, Nadal hopes to rest before the challenge against an opponent who plays well on all surfaces. Thiem took a 5-4 lead before Nadal won both service points to set up his first match point.
"I suffered, that's the right word", said Nadal after playing his longest ever match at the tournament. It's the first time he won the match after that kind of start.
In a gripping 4-hour 49-minute contest which concluded at 2.04 a.m. on Wednesday, world number one Nadal won through to keep his bid for a fourth title in NY and 18th Grand Slam crown on track.
Find out how to watch Nadal vs Thiem live online streaming with or without cable when the match starts at approximately 9 pm EST, or when the previous match concludes. Thiem was also 5-3 ahead in the third set and 4-2 in the fourth before he was reeled in by Nadal, the three-time champion in NY. That mistake might have stayed in Nadal's head, because he played terribly in the ensuing tiebreaker.
Rafael Nadal watched as his opponent hit an overhead beyond the baseline on match point and then dropped his racket to his side.
"If he decides to stand far back, Rafa will be thinking "yum yum, I can get my forehand into play".
That, Nadal would say afterward, managed to "break my heart".
"(I am) sad for him because when [he arrived at] this moment, he did all the things well to win the match.
"To reach the semifinal again here in NY in my favourite tournament is very special to me", said Del Potro after his eighth win over Isner in 12 meetings. "Forever I'm going to remember this match, for sure". He's a great guy, a close friend who will have many more opportunities to win the big titles. It was a question of a little bit of luck at the end.
The final result was 0-6, 6-4, 7-5, 6 (4) -7 and 7-6 (5) in 4 hours and 49 minutes, which is the longest match of this edition of the tournament. Happy, of course, to be in semi-finals again, it means a lot to me.
This one was never easy: Nadal trailed by a break in the third set before taking it.
Perhaps Thiem, after a change of socks and shoes, looked the fresher going into the decider but he needed to save two break points at 2-2, one with an ace, to maintain parity.
"Thiem has a good attitude on the court and in training".
At this point, Thiem had to ask for a new pair of shoes and socks because his were waterlogged from sweating so much.
Tennis. US Open. 1/four finals.
Despite that, the 29-year-old was never broken in the 3 hour 31 minute match where Isner unleashed 26 aces but was undone by 52 unforced errors compared to Del Potro's 14.