Guillermo Bujniewicz defeated Andres Molteni 6-4 6-3 in the Chile F3 round of 32 on clay. The upset overturned the form book — Andres Molteni came in leading the head-to-head 6–2, but Guillermo Bujniewicz had been the form player, winning 5 of their last 10 on clay. Guillermo Bujniewicz narrowed the head-to-head to 6–3.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2010-05-31 | Argentina F7 | QF | clay | Andres Molteni | 6-2 6-2 |
| 2009-10-26 | Argentina F21 FUTURES | R32 | clay | Andres Molteni | 6-3 2-6 6-1 |
| 2009-06-15 | Argentina F9 | R32 | clay | Andres Molteni | 6-2 6-1 |
| 2009-05-18 | Argentina F6 | SF | clay | Guillermo Bujniewicz | 6-3 6-7(5) 6-3 |
| 2008-05-19 | Argentina F3 | R32 | clay | Andres Molteni | 1-6 7-6(5) 7-6(4) |
| 2007-09-24 | Bolivia F3 | QF | clay | Andres Molteni | 4-6 6-1 6-4 |
| 2007-07-30 | Argentina F10 | QF | clay | Andres Molteni | 6-2 6-3 |
| 2006-11-20 | Uruguay F3 | QF | clay | Guillermo Bujniewicz | 6-3 6-1 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.