Semifinal 3
mardi 7 août 2018, 19h59 GMT – 19h59 GMT
| Nom | Équipe | Temps | |
|---|---|---|---|
| 1 |  Yasmaní Copello | Turkey | 48.88″ |
| 2 |  Thomas Barr | Ireland | + 0.22″ |
| 3 | Lorenzo Vergani | Italy | + 0.53″ |
| 4 | Muhammad Abdalla Kounta | FFA - France Athlétisme | + 0.7″ |
| 5 | Mate Koroknai | Hungary | + 0.89″ |
| 6 | Jack Green | Great Britain | + 0.96″ |
| 7 | Denys Nechyporenko | Ukraine | + 1.39″ |
| Aleksandr Skorobogatko | Authorised Neutral Athlete | DNF |