| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2235 | Kirani JAMES |  GRN | 43.88 Q SB | 0.160 | 
| 2 | 1551 | Anthony José ZAMBRANO |  COL | 43.93 Q AR | 0.175 | 
| 3 | 3015 | Liemarvin BONEVACIA |  NED | 44.62 q NR | 0.160 | 
| 4 | 3633 | Deon LENDORE |  TTO | 44.93 | 0.193 | 
| 5 | 2437 | Davide RE |  ITA | 44.94 SB | 0.157 | 
| 6 | 3522 | Ricky PETRUCCIANI |  SUI | 45.26 | 0.140 | 
| 7 | 3468 | Luka JANEŽIČ |  SLO | 45.36 SB | 0.152 | 
| 8 | 1201 | Jonathan SACOOR |  BEL | 45.88 | 0.136 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 3913 | Michael CHERRY |  USA | 44.44 Q | 0.162 | 
| 2 | 2634 | Christopher TAYLOR |  JAM | 44.92 Q SB | 0.164 | 
| 3 | 1097 | Steven SOLOMON |  AUS | 45.15 | 0.168 | 
| 4 | 2827 | Mazen Mawtan AL YASEN |  KSA | 45.37 | 0.154 | 
| 5 | 1274 | Leungo SCOTCH |  BOT | 45.56 | 0.178 | 
| 6 | 3625 | Machel CEDENIO |  TTO | 45.86 | 0.192 | 
| 7 | 1137 | Alonzo RUSSELL |  BAH | 46.04 | 0.169 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1136 | Steven GARDINER |  BAH | 44.14 Q SB | 0.152 | 
| 2 | 3958 | Michael NORMAN |  USA | 44.52 Q | 0.156 | 
| 3 | 1270 | Isaac MAKWALA |  BOT | 44.59 q | 0.197 | 
| 4 | 2583 | Demish GAYE |  JAM | 45.09 SB | 0.155 | 
| 5 | 3438 | Wayde VAN NIEKERK |  RSA | 45.14 | 0.381 | 
| 6 | 3019 | Jochem DOBBER |  NED | 45.48 | 0.191 | 
| 7 | 3635 | Dwight ST. HILLAIRE |  TTO | 45.58 | 0.153 | 
| 8 | 1154 | Jonathan JONES |  BAR | 45.61 | 0.159 |