Cruz Hewitt – the 17-year-old son of former world number one Lleyton Hewitt – earned his first ATP victory in his main singles draw debut.
The Australian beat fellow qualifier Marcos Giron of the United States 6-3 6-4 in 74 minutes.
His maiden win came at the Washington Open – a competition his father won in 2004.
It was one of his father’s 30 career titles, including the 2002 Wimbledon men’s singles crown.
“It’s a pretty special moment,” Hewitt said. “Seeing my dad play this tournament and to get my first tour win, it feels really cool.”
Hewitt could next play fellow Australian Alex de Minaur, the top seed and defending Washington champion.
De Minaur faces Greek Stefanos Tsitsipas on Wednesday.
Hewitt junior copied a famous celebration from his father after the victory – a right arm bicep curl.
“He just always did it and when I was little I’ve just always seen it,” Hewitt said. “It’s cool to be able to do that now because obviously my dad has been a huge part of where I am today.”
The teenager said he was inspired when he saw his father’s name on the ring of champions in Washington DC during qualifying.
“It’s very surreal,” he said. “Kind of inspirational to look up at it as well.
“I do feel pretty comfortable to be at the tournaments. It’s pretty exciting because I’ve dreamed of playing at these tournaments and I’ve seen behind the scenes and to be in the gym and the locker room with these guys, it’s pretty cool.”
