400m Nat. Hommes, Heat:1 of 4 ; Official result since 18:32
| Rank | Lane | ID | Name | PB | Team | Cat | Result | Info | Video |
| 1 | 5 | 52 | HERBAY THEO | 52.16 | BEL | Jun | 51.93 | ||
| 2 | 6 | 1377 | BERTRAND DIMITRI | 51.15 | BEL | Sen | 52.20 | ||
| 3 | 4 | 1492 | JACQUEMIN JULIAN | 51.27 | BEL | Sen | 52.40 | ||
| 4 | 7 | 9053 | WALTERS TIAAN | 53.80 | RSA | Jun | 53.81 | ||
| 5 | 2 | 1389 | AZZOUZ SOUHAIB | 51.73 | BEL | Sen | 54.37 | ||
| 3 | 2162 | BOVY VICTOR | 53.39 | BEL | Sen | DNS |