WHAT HAPPENED: Reigning US Open champion and top-seeded Rafael Nadal beat ninth-seeded Dominic Thiem in an epic, bruising US Open quarterfinal that lasted nearly five hours and finished in the early morning hours on Wednesday in Arthur Ashe Stadium.

The match ended at 2:04 a.m., with Nadal surviving, 0-6, 6-4, 7-5, 6-7, 7-6.

The four-hour, 49-minute marathon fell short of the longest match in tournament history, a five-hour, 26-minute battle between Stefan Edberg and Michael Chang in the 1992 semifinals.

“I just kept going,” said the 32-year-old Nadal about his performance.

Drained by their efforts, the players embraced at the end.

September 4, 2018 - Rafael Nadal and Dominic Thiem embrace after their match during the 2018 US Open.

“I told him that I am very sorry and you are very good,” Nadal said of the 25-year-old Austrian.

It was a physical, intense match with the majority of points being contested from the baseline. Yet, neither player looked to be fatigued at any time, racing from sideline to sideline and dashing up to cover drop shots with as much jump in their step in the last games as they had at the beginning of the match.

The quality of play was at an astounding high caliber throughout. Both players bludgeoned the ball. Thiem had 74 winners, fearlessly cracking thunderbolt forehands and one-handed backhands into corners and on the lines. He also had 18 aces.

Nadal countered with 55 winners. Never acknowledged as a great volleyer, Nadal bravely came to net at many of the crucial times in the match, winning the point 36 times.

Playing in his first US Open quarterfinal, Thiem lived dangerously in the fifth set. He saved two break points in the fifth game and three more in the 11th game. Meanwhile Nadal never faced a break point.

Thiem lost his serve to begin the decisive tiebreak. But the Austrian came right back to break Nadal for 1-1. The pair each lost their serve in the fifth and sixth points to leave things level at 3-3.

play video AI Match Highlight: Nadal vs. Thiem - QF

At 5-5 Nadal smacked a forehand winner to lift him to match point. On the final point, Thiem missed an overhead over the baseline to give the Spaniard the tiebreak 7-5 and the match.

Thiem will rue the chances he had in the third set when he had a 5-3 lead and could not serve out the set.

"Yeah, it's going to be stuck in my mind forever. Forever I'm going to remember this match, for sure," Thiem said after the match. "It's cruel sometimes, tennis, because I think this match didn't really deserve a loser. But there has to be one.

"And I would say if we skip the first set, was really open match from the beginning to the end. The way it ended up in the fifth set tiebreaker, there it's 50/50. He made one more point than me."

WHAT IT MEANS: Nadal, who also won in 2010, and 2013, will meet a familiar foe Juan Martin del Potro in the semifinals scheduled for Friday.

This will be the third meeting in the Grand Slams this year between the two, with Nadal wining both in the French Open semifinals and Wimbledon quarterfinals. Altogether Nadal leads the head to head series 11-5 over the third-seeded Argentine

MATCH POINT: The last time the 17-time Grand Slam champion had lost a set 6-0 was against German Phillip Kohlschreiber in Miami last year. Nadal won that match as well, 0-6, 6-2, 6-3.