Konstantin Don Gruber defeated Jeff Williams 6-1 6-4 in the Mexico 1 4 round of 16 on clay. The upset overturned the form book — Jeff Williams came in leading the head-to-head 1–0. Konstantin Don Gruber claimed a first win over Jeff Williams in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2001-03-12 | Mexico 1 3 | R32 | clay | Jeff Williams | 6-4 6-4 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.