Level, 1 wins each over 2 singles meetings since 2024. Last meeting on 08/07/2026 at Iasi Challenger.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 08/07/2026 | Iasi Challenger | Round 2 | clay | Kasnikowski | 6-4 3-6 5-4 |
| 26/08/2024 | U.S. Open - New York | Round 1 | hard | Portero | 6-7(6) 6-1 6-2 3-4 |
| clay | Portero 0 - 1 Kasnikowski |
| hard | Portero 1 - 0 Kasnikowski |
| 2026 | Portero 0 - 1 Kasnikowski |
| 2024 | Portero 1 - 0 Kasnikowski |
174 wins, 180 losses since 2021 (49.2%).
Last matches: D D V V V
202 wins, 119 losses since 2021 (62.9%).
Last matches: D V D V V
Level, 1 wins each over 2 singles meetings since 2024.
On 08/07/2026, at Iasi Challenger (Round 2): Maks Kasnikowski won 6-4 3-6 5-4.