| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2977 | Machel CEDENIO |  TTO | 44.98 Q | 0.179 | 
| 2 | 3093 | Gil Roberts |  USA | 45.27 Q | 0.168 | 
| 3 | 2275 | Yoandys Lescay |  CUB | 45.36 Q SB | 0.199 | 
| 4 | 2617 | Fitzroy Dunkley |  JAM | 45.66 | 0.176 | 
| 5 | 2089 | Kévin BORLÉE |  BEL | 45.90 | 0.138 | 
| 6 | 3115 | Alberth Bravo |  VEN | 46.15 | 0.205 | 
| 7 | 2697 | Alexander Lerionka Sampao |  KEN | 46.62 | 0.199 | 
| 8 | 2801 | Ousseini Djibo Idrissa |  NIG | 50.06 | 0.173 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2540 | Bralon TAPLIN |  GRN | 45.15 Q | 0.162 | 
| 2 | 2262 | Nery Brenes |  CRC | 45.53 Q | 0.151 | 
| 3 | 2125 | Karabo SIBANDA |  BOT | 45.56 Q | 0.166 | 
| 4 | 2600 | Matteo GALVAN |  ITA | 46.07 | 0.154 | 
| 5 | 2679 | Raymond Kibet |  KEN | 46.15 | 0.234 | 
| 6 | 2816 | Mehboob Ali |  PAK | 48.37 | 0.212 | 
| 7 | 2217 | Bachir MAHAMAT |  CHA | 48.59 | 0.188 | 
| 2333 | Anas Beshr |  EGY | DQ RIAAF 163.3a | 0.141 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2910 | Wayde VAN NIEKERK |  RSA | 45.26 Q | 0.147 | 
| 2 | 2327 | Luguelín SANTOS |  DOM | 45.61 Q | 0.148 | 
| 3 | 2620 | Javon FRANCIS |  JAM | 45.88 Q | 0.172 | 
| 4 | 2088 | Jonathan BORLÉE |  BEL | 46.01 | 0.162 | 
| 5 | 2685 | Alphas Leken KISHOYIAN |  KEN | 46.74 | 0.147 | 
| 6 | 3122 | Brandon Parris |  VIN | 47.62 | 0.144 | 
| 2073 | Alonzo RUSSELL |  BAH | DQ RIAAF 163.3a | 0.159 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2980 | Lalonde Gordon |  TTO | 45.24 Q | 0.153 | 
| 2 | 2929 | Luka JANEŽIČ |  SLO | 45.33 Q | 0.148 | 
| 3 | 2126 | Baboloki THEBE |  BOT | 45.41 Q | 0.155 | 
| 4 | 2063 | Chris Brown |  BAH | 45.56 SB | 0.147 | 
| 5 | 2472 | Martyn ROONEY |  GBR | 45.60 | 0.154 | 
| 6 | 2663 | Julian Jrummi WALSH |  JPN | 46.37 | 0.149 | 
| 7 | 2321 | Gustavo Cuesta |  DOM | 46.92 | 0.143 | 
| 8 | 2885 | James Nyang CHIENGJIEK |  ROT | 52.89 | 0.213 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 3090 | LaShawn Merritt |  USA | 45.28 Q | 0.235 | 
| 2 | 2880 | Abdalelah Haroun |  QAT | 45.76 Q | 0.190 | 
| 3 | 2121 | Isaac MAKWALA |  BOT | 45.91 Q | 0.242 | 
| 4 | 3027 | Vitaliy Butrym |  UKR | 45.92 | 0.166 | 
| 5 | 2587 | Donald Blair-Sanford |  ISR | 46.06 | 0.163 | 
| 6 | 2982 | Deon LENDORE |  TTO | 46.15 | 0.201 | 
| 7 | 2147 | Hederson Estefani |  BRA | 46.68 | 0.234 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2539 | Kirani JAMES |  GRN | 44.93 Q | 0.156 | 
| 2 | 2623 | Rusheen MCDONALD |  JAM | 45.22 Q SB | 0.179 | 
| 3 | 2461 | Matthew HUDSON-SMITH |  GBR | 45.26 Q | 0.142 | 
| 4 | 3102 | David Verburg |  USA | 45.48 q | 0.167 | 
| 5 | 2547 | Winston GEORGE |  GUY | 45.77 | 0.186 | 
| 6 | 2254 | Diego PALOMEQUE |  COL | 46.48 | 0.159 | 
| 2160 | Abbas Abubakar ABBAS |  BRN | DQ RIAAF 163.3a | 0.192 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2171 | Ali Khamis Khamis |  BRN | 45.12 Q | 0.161 | 
| 2 | 2065 | Steven GARDINER |  BAH | 45.24 Q | 0.149 | 
| 3 | 2780 | Liemarvin BONEVACIA |  NED | 45.49 Q | 0.142 | 
| 4 | 2849 | Rafał Omelko |  POL | 45.54 q | 0.177 | 
| 5 | 2304 | Pavel MASLÁK |  CZE | 45.54 q | 0.183 | 
| 6 | 2572 | Muhammed Anas YAHIYA |  IND | 45.95 | 0.158 | 
| 7 | 2792 | Orukpe Eraiyokan |  NGR | 47.42 SB | 0.180 | 
| 8 | 2642 | Yuzo Kanemaru |  JPN | 48.38 | 0.144 |