Niels has tallied quite a few cups, bowls and medals in his career. In addition to the Grand Slam titles listed below, Niels became World Junior Champion in 2019. He won bronze (single) and gold (doubles) at the Tokyo 2021 Paralympic Games. By winning at the European Para Championships 2023, he was assured participation in the Paralympic Games in Paris 2024. There he won gold in both singles and doubles. In addition, he is the 2022 and 2023 world champion in the quad category and won the 2021, 2023 and 2024 NEC Wheelchair singles Masters.
8
Grand slam single titles
13
Grand slam double titles
55
ITF single titles
1
ITF Quad single ranking
Australian Open
2026 single
Winner
2026 double
Winner
2025 single
Runner-up
2025 double
Runner-up
2024 single
Semifinalist
2024 doubles
Semifinalist
2023 single
Runner-up
2023 double
Winner
2022 single
Quarterfinalist
2022 double
Runner-up
2021 single
Semi-finalist
2021 double
Semi-finalist
Roland Garros
2025 single
Runner-up
2025 double
Winner
2024 single
Semifinalist
2024 doubles
Winner
2023 single
Winner
2023 double
Semi-finalist
2022 single
Winner
2022 double
Winner
Wimbledon
2025 single
Winner
2025 double
Winner
2024 single
Winner
2024 doubles
Winner
2023 single
Winner
2023 double
Winner
2022 single
Runner-up
2022 double
Winner
US Open
2025 single
Winner
2025 double
Winner
2023 single
Runner-up
2023 double
Winner
2022 single
Winner
2022 double
Winner
2021 single
Runner-up
2021 double
Winner