Kirill Mishkin defeated Rafael Mazon Hernandez 6-3 5-7 10-8 in the M15 Madrid 1 q64 on clay. The upset overturned the form book — Rafael Mazon Hernandez came in leading the head-to-head 1–0. Kirill Mishkin claimed a first win over Rafael Mazon Hernandez in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-08-29 | M25 Oviedo 1 | Q32 | clay | Rafael Mazon Hernandez | 6-3 6-3 |