Frederik Nielsen defeated Jakub Hasek 7-5 6-4 in the Great Britain F2 round of 16 on hard. The upset overturned the form book — Jakub Hasek came in leading the head-to-head 1–0. Frederik Nielsen claimed a first win over Jakub Hasek in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2004-02-09 | Switzerland 1 3 | R16 | carpet | Jakub Hasek | 6-1 3-6 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.