Sebastian Korda, the son of 1992 Roland Garros runner-up and 1998 Australian Open champion Petr Korda, defeated Andreas Seppi in the first round of the French Open on Sunday.
The 20-year-old Korda came through qualifying to earn a place in the Roland Garros main draw for the first time, and overcame the veteran Seppi 6-2, 4-6, 6-3, 6-3 in gloomy conditions.
He credited his father for his lasting support after notching his first victory at tour level.
"My dad is a really big help, he oversees everything," said Korda.
"He doesn't really travel with me that much, but we're always in contact and whenever I'm home we're always on the court together.
"He's a really big help and I don't think I would be anywhere near where I am right now without him."
Korda junior, who stands 6ft 5in (1.96m), made his Grand Slam debut at the US Open last month and won the boys' singles title at the Australian Open two years ago.
Born in Florida to Czech parents, Korda represents the United States and is also the younger brother of Jessica and Nelly, both successful golfers on the LPGA Tour.
Ranked 212 in the world, he will meet the towering John Isner, the 21st seed, for a place in the third round.
"Just playing against the bigger guys gave me a lot of confidence," said Korda, who lost to Denis Shapovalov as a wild card in four sets in New York.
"It gave me belief that I could keep up with these guys and play with them."
Korda is not the only son of a former Grand Slam winner in the men's Roland Garros main draw this year.
He is joined in the field by Emilio Gomez, who was born 18 months after his father Andres defeated Andre Agassi in the 1990 French Open final.