Sebastian Romano defeated Oscar Bustos 2-6 6-4 6-0 in the Bolivia Chile Masters 2 qualifying round on clay. The upset overturned the form book — Oscar Bustos came in leading the head-to-head 2–0. Sebastian Romano claimed a first win over Oscar Bustos in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-09-23 | Ecuador Peru Masters 3 | QF | clay | Oscar Bustos | 7-5 6-1 |
| 1991-05-13 | Brazil 3 Masters 2 | R32 | clay | Oscar Bustos | 1-6 6-3 7-5 |