400 m M (Dec) | M | 400(10) | WM400 | Heat 1 | 2024-08-31 | 18:00:00 | 18:01:19 | | | | | | | |
| | | | | | | | | | | | | | |
1 | 5 | 1 | 11 | MARUYAMA Yuma | 98-06-03 | JAPAN | 48.96/22 | 50.45 | 49.43 | | | SB | 841 | 5 |
2 | 4 | 1 | 18 | MATHYS Nik | 00-04-20 | SWITZERLAND | 49.78/24 | 49.78 | 49.75 | | | PB | 826 | 7 |
3 | 6 | 1 | 10 | NAIDON Lorenzo | 99-06-15 | ITALY | 49.25/23 | 50.70 | 50.14 | | | SB | 808 | 8 |
4 | 3 | 1 | 12 | BENKUNSKAS Edgaras | 99-05-28 | LITHUANIA | 49.73/23 | 49.93 | 51.64 | | | | 741 | 9 |
| 2 | 1 | 2 | DOUBEK František | 02-04-04 | CZECHIA | 48.72/21 | | DNS | | | | | |