Frances Tiafoe won the Delray Beach Open, with father Frances Sr.
The 91st-ranked Tiafoe, the first wild-card recipient to win the title in its 26-year history, had consecutive aces on the final two points for a 6-1, 6-4 victory over Peter Gojowczyk of Germany.
He entered last week’s New York Open, where he reached the quarterfinals, with nine total career ATP tour-level match victories.
Tiafoe was the last American to defeat the German, which took place at the 2016 Winnetka, Illinois Challenger event.
Gojowczyk had beaten his eight previous American opponents in ATP tour-level matches, including sixth-seeded John Isner, Reilly Opelka and Steve Johnson this week.
Overall, Gojowczyk had beaten the last 14 American players he faced in tour and non tour-level matches since that Winnetka loss to Tiafoe.