Jacco Van Duyn defeated Piet Norval 6-4 6-4 in the Great Britain 2 Masters 3 qualifying round on hard. The upset overturned the form book — Piet Norval came in leading the head-to-head 2–0. Jacco Van Duyn claimed a first win over Piet Norval in three meetings, narrowing the head-to-head to 2–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-04-22 | Great Britain 2 Masters 2 | R16 | hard | Piet Norval | 7-5 6-1 |
| 1991-04-22 | Great Britain 2 Masters 4 | SF | hard | Piet Norval | 7-5 7-6 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.