Tiafoe beat Nakashima 7-5, 6-3 in Cincinnati, breaking at the end of each set to secure the win. He saved three of five break points and converted two of five; Nakashima had identical conversion numbers.
The first set saw four consecutive breaks from games 3-6, with Tiafoe twice moving ahead and Nakashima twice levelling. Tiafoe then broke to lead 6-5 and took the set 7-5. In the second set he broke for a 3-2 lead and again in game nine to close it out 6-3.
Tiafoe's returning was the difference: despite landing only 42% of first serves and hitting three double faults, he won 13 return points to Nakashima's 10. Nakashima put 54% of first serves in play and hit two aces, but Tiafoe's pressure on return decided the match.