Thiago Monteiro defeated Roberto Carballes Baena 6-2 6-3 in the Buenos Aires round of 32 on clay. The upset overturned the form book — Roberto Carballes Baena came in ranked #203, defending last year's round of 16, but Thiago Monteiro had been the form player, winning 7 of their last 10 on clay. Thiago Monteiro extended the head-to-head to 3–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-02-22 | Cordoba | R16 | clay | Thiago Monteiro | 6-3 6-4 |
| 2020-02-24 | Santiago | R16 | clay | Thiago Monteiro | 6-1 6-4 |
Averages from each player's recent completed matches (20 vs 20). ATP, WTA & Challenger.