Stadium: Stadium Round: 25 Ground: Hardcourt outdoor
| ITF M15 Ithaca | 2021/10/07 16:05 | A.J Catanzariti v Nathan Ponwith | 6-4,6-3 |
| ITF M15 Ithaca | 2021/10/06 15:00 | Evan Bynoe v Nathan Ponwith | 4-6,6-4,1-6 |
| ITF M15 Lubbock | 2021/09/28 15:00 | Garrett Johns v Nathan Ponwith | 6-3,6-2 |
| ITF M15 Fayetteville | 2021/09/21 17:00 | Nathan Ponwith v Juncheng Shang | 0-6,6-3,5-7 |
| ITF M15 Champaign | 2021/09/17 15:00 | Nathan Ponwith v Martin Damm | 6-7,4-6 |
| ITF M15 Champaign | 2021/09/16 17:00 | Nathan Ponwith v Blaise Bicknell | 6-2,6-4 |
| ITF M15 Champaign | 2021/09/15 19:40 | Ryan Shane v Nathan Ponwith | 5-7,2-6 |
| ITF M25 Decatur | 2021/08/04 18:45 | Yunseong Chung v Nathan Ponwith | 6-2,6-1 |
| Challenger Maui | 2017/01/25 20:00 | Andre Ilagan v Zhe Li | 1-6,0-6 |