Denis Shapovalov beat Taylor Fritz 7-5, 6-4 to advance to the semi-finals of the ATP Delray Beach Open.
Shapovalov is vying to become the first 18-year-old since Kei Nishikori at Delray Beach in 2000 to win an ATP Tour title.
He'll face either Chung Hyeon or Frances Tiafoe for a place in the final.
But first, Tiafoe and Chung will have to complete their rain-disrupted contest, which was halted with Tiafoe leading 5-7, 6-4, 5-3.
Organizers waited several hours to try to get the contest completed, finally calling off play for the day after midnight.
The two were scheduled to return on Saturday afternoon to complete their match, which will be followed by the first semi-final between Peter Gojowczyk and Steve Johnson, a 6-1, 6-4 winner over Evgeny Donskoy.
Chung is the last seed left in the field.
With many up-and-coming players reaching the quarter-finals, Shapovalov said it "almost feels like a junior tournament".
"So many young guys in the quarters and going to be in the semis," he said. "It's good to see a little bit of a new generation of tennis, a new era beginning to happen."
Shapovalov saved both break points he faced against Fritz, wrapping up the victory in one hour and 16 minutes.
"I played really well," he said. "I felt really comfortable from the warm-up. I felt really good with my timing and I returned well when I needed to."
