Jason Cask defeated Donald Johnson 6-2 6-1 in the Australia 2 Masters 3 qualifying round on hard. The upset overturned the form book — Donald Johnson came in leading the head-to-head 1–0. Jason Cask claimed a first win over Donald Johnson in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1991-08-12 | Australia 2 Masters 1 | R32 | hard | Donald Johnson | 6-3 6-3 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.