Per Thornadtsson defeated Jacob Adaktusson 6-7 7-6 6-2 in the Ukraine F4 qualifying round on clay. The upset overturned the form book — Jacob Adaktusson came in leading the head-to-head 1–0. Per Thornadtsson claimed a first win over Jacob Adaktusson in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1999-09-27 | Sweden F2 | R16 | hard | Jacob Adaktusson | 6-4 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.