Markos Kalovelonis defeated Ioannis Stergiou 6-4 6-2 in the M15 Heraklion 3 round of 32 on hard. The upset overturned the form book — Ioannis Stergiou came in leading the head-to-head 1–0. Markos Kalovelonis claimed a first win over Ioannis Stergiou in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2018-03-26 | Greece F5 | R32 | hard | Ioannis Stergiou | 6-3 6-2 |
Averages over each player's completed matches in the selected window. ATP, WTA & Challenger.