Guilherme Clezar
Guilherme Sarti Clezar , is a tennis player from Brazil. He played in several ATP 250 events, including the 2011 Brasil Open. Clezar plays mainly in ATP Challenger Tour events.Singles: 7 (2–5)
| Outcome | No. | Date | Tournament | Surface | Opponent | Score |
| Winner | 1. | | Rio Quente, Brazil | Hard |  Paul Capdeville | 7–6, 6–3 |
| Winner | 2. | | Campinas, Brazil | Clay |  Facundo Bagnis | 6–4, 6–4 |
| Runner-up | 1. | | São Paulo, Brazil | Clay | Diego Schwartzman | 2–6, 3–6 |
| Runner-up | 2. | | Santiago, Chile | Clay | Facundo Bagnis | 2–6, 7–5, 2–6 |
| Runner-up | 3. | | Rio de Janeiro, Brazil | Clay | Facundo Bagnis | 4–6, 6–4, 2–6 |
| Runner-up | 4. | | Liberec, Czech Republic | Clay |  Pedro Sousa | 4–6, 7–5, 2–6 |
| Runner-up | 5. | | Cali, Colombia | Clay | Facundo Bagnis | 6–7, 5–7 |
