Mark Merklein defeated Chad Clark 7-6 6-0 in the USA 3 Masters 1 qualifying round on hard. The upset overturned the form book — Chad Clark came in leading the head-to-head 1–0. Mark Merklein claimed a first win over Chad Clark in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 1993-07-09 | USA 4 Masters 4 | R32 | hard | Chad Clark | 5-7 7-6 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.