Semifinal 2
mardi 7 août 2018, 19h52 GMT – 19h52 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Rasmus Mägi | Estonia | 48.8″ |
| 2 |  Ludvy Vaillant | FFA - France Athlétisme | + 0.08″ |
| 3 | Timofey Chalyy | Authorised Neutral Athlete | + 0.09″ |
| 4 | Sergio Fernández | Spain | + 0.39″ |
| 5 | Tibor Koroknai | Hungary | + 0.44″ |
| 6 | Martin Kucera | Slovakia | + 1.5″ |
| 7 | Maksims Sincukovs | Latvia | + 1.53″ |
| 8 | Alain-Hervé Mfomkpa | Switzerland | + 1.91″ |