Jan Kumstat
2025
| Australian Open Junior | [1] | Quarter |
| J300Traralgon | [1] | 3R |
2024
| J500Plantation | [3] | 2R |
| J300Bradenton | [2] | 1R |
| J300Beijing | [1] | Semi |
| Wimbledon Junior | [6] | 2R |
| J300Plovdiv | [1] | Win |
| J500Cairo | [1] | 2R |
| Australian Open Junior | Final | |
| J300Traralgon | 2R |
2023
| J300Beijing | [6] | Semi |
| J200Rakovnik | [2] | Final |
| J300Pancevo | 2R | |
| J300Prague | [10] | Quarter |
| J300Bamberg | 3R |
Nation
CZE
Generation
Born in 2007 (17-18 years old)
Year-end Junior World Ranking
- Year-end 2024 9th
- Year-end 2023 70th
- Year-end 2022 231th
- Year-end 2021 977th
Rival
Dominick Mosejczuk (2-0)
Izan Almazan Valiente (2-0)
Oliver Bonding (1-1)
Jagger Leach (1-1)
Anas Mazdrashki (1-1)
Match Details
2025 Australian Open Junior
| W | 1R | Maximus Dussault | 6-2 6-2 |
| W | 2R | Cruz Hewitt | 6-3 7-6 |
| W | 3R | Moise Kouame | 6-3 3-6 6-3 |
| L | QF | Henry Bernet | 6-7 6-7 |
2025 J300Traralgon
| W | 1R | Luis Guto Miguel | 6-2 6-3 |
| W | 2R | Dominick Mosejczuk | 6-1 6-2 |
| L | 3R | William Rejchtman Vinciguerra | 7-6 5-7 2-6 |
2024 J500Plantation
| W | 1R | Dominick Mosejczuk | 4-6 6-3 6-3 |
| L | 2R | Timofei Derepasko | 4-6 6-1 4-6 |
2024 J300Bradenton
| L | 1R | Sasha Colleu | 1-6 1-6 |
2024 J300Beijing
| W | 2R | Ye Chen | 6-3 6-1 |
| W | 3R | Kerem Yilmaz | 6-3 6-3 |
| W | QF | Nikita Bilozertsev | 6-2 3-0 |
| L | SF | Oliver Bonding | 2-6 4-6 |
2024 Wimbledon Junior
| W | 1R | Alexander Vasilev | 4-6 7-6 7-6 |
| L | 2R | Jagger Leach | 4-6 6-7 |
2024 J300Plovdiv
| W | 1R | Sergio Planella Hernandez | 6-4 6-4 |
| W | 2R | Gabriel Ghetu | 6-4 6-3 |
| W | QF | Theo Papamalamis | 7-6 7-5 |
| W | SF | Anas Mazdrashki | 2-6 6-0 6-3 |
| W | F | Izan Almazan Valiente | 6-4 4-6 6-2 |
2024 J500Cairo
| W | 1R | Lovro Maricic | 6-3 6-3 |
| L | 2R | Pierluigi Basile | 6-4 5-7 |
2024 Australian Open Junior
| W | 1R | Tianhui Zhang | 6-4 6-3 |
| W | 2R | Charlie Robertson | 6-7 7-6 6-3 |
| W | 3R | Alexander Razeghi | 7-6 6-2 |
| W | QF | Hayden Jones | 6-7 6-2 7-5 |
| W | SF | Mees Rottgering | 6-1 6-3 |
| L | F | Rei Sakamoto | 6-3 6-7 5-7 |
2024 J300Traralgon
| W | 1R | Jagger Leach | 6-3 6-4 |
| L | 2R | Pavle Marinkov | 4-6 3-6 |
2023 J300Beijing
| W | 2R | Eren Matthew Cheung | 6-1 6-4 |
| W | 3R | Goncalo Marques | 7-6 7-6 |
| W | QF | Oliver Bonding | 6-2 2-6 6-3 |
| L | SF | Benjamin Gusic Wan | 3-6 1-6 |
2023 J200Rakovnik
| W | 2R | Krystof Svojgr | 6-4 6-4 |
| W | 3R | Andreas Loizas | 6-3 7-5 |
| W | QF | Lorenzo Angelini | 6-4 6-3 |
| W | SF | Izan Almazan Valiente | 6-2 7-5 |
| L | F | Adrien Berrut | 4-6 4-6 |
2023 J300Pancevo
| W | 1R | Danial Rakhmatullayev | 6-2 6-2 |
| L | 2R | Anas Mazdrashki | 6-7 4-6 |
2023 J300Prague
| W | 2R | Jan Klimas | 7-5 6-4 |
| W | 3R | Aleksa Pisaric | 6-7 7-6 6-2 |
| L | QF | Jakub Filip | 4-6 7-6 4-6 |
2023 J300Bamberg
| W | 1R | Manvydas Balciunas | 6-1 6-7 6-4 |
| W | 2R | Max Dahlin | 6-2 4-3 |
| L | 3R | Diego Dedura-Palomero | 6-7 5-7 |
Junior Tennis Database is a site that summarizes the results of ITF junior tennis tournaments.
Number of registered tournaments: 5774, Number of registered players: 3,011, Number of registered results: 222,093