If this semifinal had, indeed, concluded right then and there, no one could have complained about the product. It would proceed for a total of 4 hours, 19 minutes.
They wore matching shirts - red in front, white in back, burgundy on the side - and were every bit each other's equal for lengthy stretches, including until 6-all in the opening tiebreaker.
Alcaraz, who by then already had saved four set points, offered up a fifth by sending a backhand wide, then made converting that one easy for Tiafoe by double-faulting. As the crowd roared, Alcaraz hung his head, walked to his sideline seat and smacked his equipment bag with his racket.
He regrouped and broke to go up in the second set, and a pivotal juncture arrived with Alcaraz serving at 5-3 but facing a break point. He snapped a cross-court forehand winner to erase that chance for Tiafoe, which began a run in which Alcaraz grabbed 11 consecutive points and 19 of 22 to own that set and a 4-0 lead in the third.
As on that forehand, Alcaraz often rips the ball with abandon - and, somehow, with precision, too, aiming for the lines and finding them. He won no fewer than three first-set points with shots that caught the outer edge of the white paint with no margin to spare.
After one, Tiafoe went over for a little light-hearted exchange with Alcaraz's coach, Juan Carlos Ferrero, the 2003 French Open champion who briefly was No. 1 himself. Yet make no mistake: Alcaraz is not some hang-back baseliner. He has a varied, all-court game and showed off his skills by winning points via acrobatic volleys, feathered drop shots and perfectly parabolic lobs.
Other than that lull in the second and third sets, and late in the fifth, Tiafoe was exceptional, too, and having the time of his life all the while.
"I'm going to be back," Tiafoe said, "and I will win this thing one day."