Shunsuke Mitsui defeated Perry Gregg 6-7 6-3 6-1 in the M25 East Lansing 1 round of 32 on hard. The upset overturned the form book — Perry Gregg came in leading the head-to-head 1–0, but Shunsuke Mitsui had been the form player, winning 6 of their last 10 on hard. Shunsuke Mitsui claimed a first win over Perry Gregg in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2023-10-04 | M15 Ithaca 2 | R32 | hard | Perry Gregg | 6-3 7-6(6) |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.