[120] Mackenzie McDonald 6-2,3-6,5-7 John Isner [28] 2021-03-27 01:05
Stadium: Grandstand Round: 24 Ground: Hardcourt outdoor
Home History
| ATP Miami | 2021/03/24 21:30 | Vasek Pospisil v Mackenzie McDonald | 3-6,6-4,3-6 |
| ATP Miami | 2021/03/23 15:45 | Mackenzie McDonald v Ivo Karlovic | 7-6,6-4 |
| ATP Miami | 2021/03/22 16:25 | Mackenzie McDonald v Roberto Cid Subervi | 6-1,6-1 |
| ATP Marseille | 2021/03/10 15:10 | Karen Khachanov v Mackenzie McDonald | 7-6,6-4 |
| ATP Marseille | 2021/03/09 12:30 | Stefano Travaglia v Mackenzie McDonald | 6-7,6-7 |
| Challenger Nur-Sultan | 2021/03/04 07:35 | Mackenzie McDonald v Tomas Machac | 4-6,1-6 |
| Challenger Nur-Sultan | 2021/03/02 09:45 | Mackenzie McDonald v Brayden Schnur | 6-3,4-6,6-4 |
| Challenger Nur-Sultan | 2021/02/28 13:00 | Mackenzie McDonald v Jurij Rodionov | 6-1,6-2 |
Away History
| ATP Acapulco | 2021/03/18 04:00 | Stefanos Tsitsipas v John Isner | 6-3,6-2 |
| ATP Acapulco | 2021/03/16 01:20 | John Isner v Salvatore Caruso | 6-4,6-3 |
| ATP Delray Beach | 2021/01/11 23:00 | Sebastian Korda v John Isner | 6-3,4-6,6-3 |
| ATP Delray Beach | 2021/01/10 01:35 | Thiago Monteiro v John Isner | 4-6,6-7 |
| French Open | 2020/09/30 09:30 | Sebastian Korda v John Isner | 6-4,6-4,2-6,6-4 |
| French Open | 2020/09/27 11:30 | Elliot Benchetrit v John Isner | 4-6,1-6,3-6 |
| US Open | 2020/08/31 22:30 | Steve Johnson v John Isner | 6-7,6-3,6-7,6-3,7-6 |
| ATP New York | 2020/08/25 21:30 | John Isner v Stefanos Tsitsipas | 6-7,6-7 |