Nakashima beat Medvedev 6-7, 7-6, 6-1 in Cincinnati, coming through after two tense tie-break sets. He took the only break of the deciding set to seal the win.
The opening set had a break for each player before Medvedev won the first tie-break. Nakashima saved all three break points he faced in the second set, levelled with a tie-break win, then converted the decisive break in the decider.
Nakashima did it with steadiness on serve: one double fault against Medvedev's nine, plus a 108-101 edge in total points. A 10-point winning run in the third set broke the match open.