In the second-longest match and the latest-ever finish in US Open history, No. 3 Carlos Alcaraz beat No. 11 Jannik Sinner to move on to the semifinal round. 

The match ended at 2:50 a.m. ET, as these players just wouldn't quit. It came down to the fifth set where the 19-year-old Alcaraz finally closed it out for a final score of 6-3, 6-7, 6-7, 7-5, 6-3, and he just laid on the court in awe that it was over. 

"I don't know how I did it," he said after the match. 

Sinner almost got the job done in the fourth set, but Alcaraz avoided the match point and ended up forcing that fifth set. 

CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COM

"I always say you have to believe in yourself all the time," Alcaraz said.

Despite everyone in Arthur Ashe Stadium being tired, the tension and suspense was palpable. Proof of that came when Sinner secured a break point to make it 3-2 in the fifth set. However, Alcaraz would break him in the next game and wouldn't lose one from there.

FRANCES TIAFOE BECOMES FIRST AMERICAN TO MAKE US OPEN MEN'S SEMIFINAL SINCE 2006

"Honestly, thank you to all of you," Alcaraz said to the crowd, thanking them for having energy from start to finish.

"I couldn't believe the energy I received here."

NICK KYRGIOS SMASHES RACKETS DURING POST-GAME MELTDOWN: ‘HONESTLY FEEL LIKE S---’

The first set went to Alcaraz pretty easily, but Sinner made things much tougher for his opponent from there. Despite Alcaraz wowing the crowd with a behind-the-back return in the second set, Sinner had the match in his hands. Until he didn't. 

No matter which way you put it, this match was electric between two of the young phenoms in the sport, and one that everyone who stayed up to watch will not forget. 

Alcaraz will be taking on American Frances Tiafoe in the semifinal on Friday, where Tiafoe is the first Black player to reach the semifinal since Arthur Ashe.