S. Sierra and C. Monnet are level 1-1 in their head-to-head since 2018 over 2 matches.
| Surface | S. Sierra | C. Monnet |
|---|---|---|
| Clay | 1 | 1 |
| Date | Winner | Score | Event |
|---|---|---|---|
| May 12, 2026 | S. Sierra | 2 - 0 | Parma · 1/16-finals · clay |
| Oct. 22, 2025 | C. Monnet | 2 - 0 | Florianopolis · 1/8-finals · clay |