“He’s a great guy and he’s improving a lot,” Sousa, 29, said of Tiafoe. “He’s going to reach a lot of finals.”

Playing in front of a crowd vociferously and unanimously supporting his opponent was a new experience that “didn’t feel great,” Tiafoe said, but there were plenty of positives to draw from the week. His semifinal performance, a 6-2, 6-3 thrashing of 11th-ranked Pablo Carreño Busta, was especially impressive. He also saved three match points in an opening-round victory over Tennys Sandgren.

“It was an unbelievable week, and I hope I can just keep it going,” Tiafoe said.

He has been considered one of the greatest prospects in his generation from a young age, but since turning pro in 2015 he has achieved relatively little at the tour level.

He drew some attention for five-set losses in the first round of the United States Open against John Isner in 2016 and Roger Federer in 2017, but coming into the 2018 season, Tiafoe had won only nine of his 38 career main-draw matches on the ATP Tour. Only one of those victories came against a top-30 opponent.

Tiafoe has 15 wins already this season, including six against top-30 opponents. He reached his first tour quarterfinal at the New York Open in February, and won his first title in Delray Beach, Fla., one week later.