Poland's No 2 seed Hubert Hurkacz reached the second round of the Japan Open tennis tournament with a 6-4, 6-7 (5/7), 6-4 win over American Marcos Giron on Wednesday.
Hurkacz was playing his first match since losing to Australian Jordan Thompson in the second round of the US Open last month.
US Open finalist Taylor Fritz is the top seed in Tokyo.
He takes on France's Arthur Fils in his first match on Thursday.
Fellow American Ben Shelton returns to Tokyo to defend his title, while US Open semifinalist Frances Tiafoe, Norway's Casper Ruud and Greece's Stefanos Tsitsipas are also competing.
The Netherlands' Botic van de Zandschulp, who knocked Spain's Carlos Alcaraz out of the US Open, was eliminated in the first round after losing 6-3, 6-4 to Italy's Matteo Berrettini.