Frances Tiafoe avenged his defeat by Ben Shelton at last year's US Open by beating the 13th seed in an all-American five-set thriller to reach the fourth round.
The pair, who are good friends, faced each other in the quarter-finals in New York last year with Shelton emerging as the victor.
But it was the lower-ranked Tiafoe who won on Friday, coming from behind twice to triumph 4-6 7-5 6-7 (5-7) 6-4 6-3 after more than four entertaining hours on Arthur Ashe Stadium.
"Ben is an incredible player, he really is. He goes for all kinds of shots, he's got no care in the world.