Per Thornadtsson defeated Joseph Sirianni 6-2 6-2 in the Denmark Masters 4 round of 32 on clay. The upset overturned the form book — Joseph Sirianni came in leading the head-to-head 1–0. Per Thornadtsson claimed a first win over Joseph Sirianni in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1997-07-26 | Baltic Masters 3 | R32 | clay | Joseph Sirianni | 6-3 6-7 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.