Stadium: M2 Round: 19 Ground: Clay
| French Open | 2021/05/26 15:30 | Zhizhen Zhang v Peter Gojowczyk | 0-6,6-7 |
| French Open | 2021/05/25 14:25 | Lorenzo Giustino v Zhizhen Zhang | 7-5,5-7,2-6 |
| Challenger Biella | 2021/05/21 12:50 | Thanasi Kokkinakis v Zhizhen Zhang | 6-2,4-6,6-3 |
| Challenger Biella | 2021/05/20 11:25 | Thai-Son Kwiatkowski v Zhizhen Zhang | 4-6,6-7 |
| Challenger Biella | 2021/05/19 09:00 | Flavio Cobolli v Zhizhen Zhang | 6-4,4-6,2-6 |
| Challenger Biella | 2021/05/17 12:00 | Borna Gojo v Zhizhen Zhang | 3-6,6-4,2-6 |
| Challenger Zagreb | 2021/05/10 08:30 | Zhizhen Zhang v Ramkumar Ramanathan | 3-6,6-7 |
| Challenger Zagreb | 2021/05/09 08:30 | Zhizhen Zhang v Dimitar Kuzmanov | 4-6,6-2,6-3 |
| French Open | 2021/05/26 17:15 | Alejandro Tabilo v Sumit Nagal | 6-3,6-3 |
| French Open | 2021/05/25 17:30 | Roberto Marcora v Sumit Nagal | 3-6,3-6 |
| Challenger Heilbronn | 2021/05/13 10:00 | Bernabe Zapata Miralles v Sumit Nagal | 6-3,6-1 |
| Challenger Heilbronn | 2021/05/12 08:30 | Antoine Hoang v Sumit Nagal | 6-1,1-6,4-6 |
| Challenger Heilbronn | 2021/05/10 13:20 | Sumit Nagal v Denis Kudla | 7-5,1-6,6-1 |
| Challenger Prague | 2021/05/07 13:00 | Norbert Gombos v Sumit Nagal | 6-4,6-2 |
| Challenger Prague | 2021/05/06 10:00 | Sergiy Stakhovsky v Sumit Nagal | 6-4,1-6,4-6 |
| Challenger Prague | 2021/05/04 10:25 | Zdenek Kolar v Sumit Nagal | 2-6,4-6 |