Mariano Kestelboim defeated Facundo Juarez 6-4 4-6 6-2 in the M25 Gandia 1 quarter-final on clay. The upset overturned the form book — Facundo Juarez came in leading the head-to-head 1–0. Mariano Kestelboim claimed a first win over Facundo Juarez in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-06-26 | M15 Antalya 25 | SF | clay | Facundo Juarez | 6-1 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.