Marc Sieber defeated Gianluigi Quinzi 7-5 6-4 in the Turkey F2 qualifying round on hard. The upset overturned the form book — Gianluigi Quinzi came in leading the head-to-head 1–0. Marc Sieber claimed a first win over Gianluigi Quinzi in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2018-01-08 | Turkey F1 | F | hard | Gianluigi Quinzi | 3-6 6-3 6-3 |
Averages over each player's completed matches in the selected window (27 vs 80). ATP, WTA & Challenger.
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About