The 4:48 match was the longest of Thiem's career and the longest match Nadal has played at the U.S. Open.
Rafael Nadal outlasted Dominic Thiem in an epic five-setter that lasted nearly five hours and didn't finish until after 2 a.m. local time.
In the end, the top-seeded and defending champion Nadal moved into the U.S. Open semifinals with an 0-6, 6-4, 7-5, 6-7, 7-6 win over Thiem in what was a rematch of this year's French Open final.
The 4:48 match was the longest of Thiem's career—the 25-year-old had never played a match longer than four hours—and the longest one Nadal has played at the U.S. Open.
The two players combined for 129 winners—74 for Thiem, 55 for Nadal—and Thiem actually won six more points overall than Nadal did.
In the final set tiebreaker, the two men traded early mini-breaks to get back on serve. Thiem took a 5-4 lead before Nadal won both service points to set up his first match point. The win was sealed when Thiem missed a difficult overhead smash long, and Nadal looked to the sky, equal parts overjoyed and relieved.
When the match was finished, Nadal hopped over the net and embraced his good friend Thiem. After the match, he told the crowd he felt badly for Thiem but suggested the best is yet to come for the young Austrian. The quarterfinal exit marks the deepest run Thiem has made at a major other than Roland Garros.
Next up for Nadal will be Juan Martin del Potro, who advanced to the semis via a four-set win over American John Isner. The two players met in the semis at last year's U.S. Open, a match Nadal won in four sets.
Earlier in the night session inside a hot and humid Arthur Ashe, Serena Williams advanced to the semis with a 6-4, 6-3 win over Karolina Pliskova.