Seita Watanabe defeated Emil Reinberg 4-6 6-3 6-4 in the M15 Cancun 3 round of 16 on hard. The upset overturned the form book — Emil Reinberg came in leading the head-to-head 1–0. Seita Watanabe claimed a first win over Emil Reinberg in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-05-31 | M15 Monastir 20 | Q32 | hard | Emil Reinberg | 7-6(4) 7-5 |
Averages over each player's completed matches in the selected window (40 vs 3). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About