David Klier defeated Ilia Kushev 6-3 6-1 in the Bulgaria 1 1 qualifying round on clay. The upset overturned the form book — Ilia Kushev came in leading the head-to-head 1–0. David Klier claimed a first win over Ilia Kushev in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2006-05-01 | Bulgaria 1 2 | SF | clay | Ilia Kushev | 6-3 6-0 |