Dominic Thiem defeated Denis Istomin 6-2 7-5 in the St. Petersburg quarter-final on carpet. The result followed the form book — Dominic Thiem came in leading the head-to-head 1–0. Dominic Thiem extended the head-to-head to 2–0.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2015-08-31 | US Open | R64 | hard | Dominic Thiem | 6-4 6-4 1-0 RET |
Averages from each player's recent completed matches (20 vs 20). ATP, WTA & Challenger.