
Alexander Zverev defeated John Isner 6-4 7-5 in the Madrid Masters quarter-final on clay. The result followed the form book — Alexander Zverev came in leading the head-to-head 6–2, defending last year's quarter-final. Alexander Zverev extended the head-to-head to 7–2.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2021-09-24 | Laver Cup | RR | hard | Alexander Zverev | 7-6 6-7 |
| 2019-09-20 | Laver Cup | RR | hard | John Isner | 6-7 6-4 |
| 2018-11-12 | Tour Finals | RR | hard | Alexander Zverev | 7-6 6-3 |
| 2018-09-21 | Laver Cup | RR | hard | Alexander Zverev | 3-6 7-6 |
| 2018-03-19 | Miami Masters | F | hard | John Isner | 6-7 6-4 6-4 |
| 2017-05-15 | Rome Masters | SF | clay | Alexander Zverev | 6-4 6-7 6-1 |
| 2017-03-20 | Miami Masters | R32 | hard | Alexander Zverev | 6-7 7-6 7-6 |
| 2016-10-10 | Shanghai Masters | R64 | hard | Alexander Zverev | 6-4 6-2 |
Averages over each player's completed matches in the selected window (199 vs 200). 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
Per-surface Serve / Return Rating (0–100, percentile within the clay field, opponent-adjusted over 52 weeks). About