Boris Borgula defeated Marko Tkalec 6-4 6-3 in the Croatia 2 Masters 4 qualifying round on clay. The upset overturned the form book — Marko Tkalec came in leading the head-to-head 2–0. Boris Borgula claimed a first win over Marko Tkalec in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2003-11-10 | Czech Rep F6 | R32 | carpet | Marko Tkalec | 2-1 |
| 1999-06-28 | Hungary F3 | R32 | clay | Marko Tkalec | 6-2 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.