Gregoire Jacq defeated Yannick Mertens 7-5 6-2 in the Rennes CH qualifying round 1 on hard. The upset overturned the form book — Yannick Mertens came in leading the head-to-head 4–0, but Gregoire Jacq had been the form player, winning 2 of their last 4 on hard. Gregoire Jacq claimed a first win over Yannick Mertens in five meetings, narrowing the head-to-head to 4–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2019-10-17 | M25+H Rodez 1 | R16 | hard | Yannick Mertens | 6-3 6-3 |
| 2019-09-21 | M25+H Plaisir 1 | SF | hard | Yannick Mertens | 6-4 7-6(7) |
| 2016-09-19 | France F19 | R16 | hard | Yannick Mertens | 6-4 6-2 |
| 2015-03-02 | France F4 | R16 | hard | Yannick Mertens | 6-4 6-7(10) 6-1 |
Averages over each player's completed matches in the selected window (52 vs 142). 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