Mert Ramadan defeated Stefan Luckanov 6-1 6-4 in the M15 Sozopol 1 q32 on hard. The upset overturned the form book — Stefan Luckanov came in leading the head-to-head 1–0. Mert Ramadan claimed a first win over Stefan Luckanov in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-10-10 | M15 Sozopol 3 | Q64 | hard | Stefan Luckanov | 7-6(4) 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.