Adam Thompson defeated Chris Klingemann 3-6 6-1 6-2 in the Mexico F7 qualifying round on hard. The upset overturned the form book — Chris Klingemann came in leading the head-to-head 1–0. Adam Thompson claimed a first win over Chris Klingemann in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2008-07-21 | USA F19 | R32 | hard | Chris Klingemann | 6-2 6-3 |