Mischa Zverev defeated John Isner 6-7 6-7 6-4 7-6 9-7 in the Australian Open round of 64 on hard. The upset overturned the form book — John Isner came in leading the head-to-head 4–2, defending last year's round of 16, but Mischa Zverev had been the form player, winning 3 of their last 6 on hard. Mischa Zverev narrowed the head-to-head to 4–3.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2020-02-24 | Acapulco | R32 | hard | John Isner | 6-3 7-6(4) |
| 2018-07-23 | Atlanta | QF | hard | John Isner | 7-5 4-6 6-1 |
| 2017-08-28 | US Open | R32 | hard | Mischa Zverev | 6-4 6-3 7-6(5) |
| 2017-05-22 | Geneva | R16 | clay | Mischa Zverev | 6-4 6-7(5) 6-3 |
| 2016-10-31 | Paris Masters | R64 | hard | John Isner | 7-6(8) 6-4 |
| 2009-09-28 | Bangkok | R16 | hard | John Isner | 7-6(5) 6-4 |
Each player's serve crossed against the other's return, converted to expected hold of serve. Recent completed matches, ATP, WTA & Challenger. About
Averages over each player's completed matches in the selected window (189 vs 200). ATP, WTA & Challenger.