Ignacio Monzon defeated Ryusei Makiguchi 1-6 6-1 6-2 in the Croatia F4 round of 32 on clay. The upset overturned the form book — Ryusei Makiguchi came in leading the head-to-head 1–0, but Ignacio Monzon had been the form player, winning 6 of their last 10 on clay. Ignacio Monzon claimed a first win over Ryusei Makiguchi in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2015-08-17 | Argentina F9 | R32 | clay | Ryusei Makiguchi | 6-0 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.