Konstantin Don Gruber defeated Jun Kato 4-6 6-3 6-3 in the New Zealand F1 round of 16 on hard. The upset overturned the form book — Jun Kato came in leading the head-to-head 1–0. Konstantin Don Gruber claimed a first win over Jun Kato in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2003-03-03 | New Zealand F2 | QF | hard | Jun Kato | 5-7 6-3 2-0 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.