| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 341 | Timothy Benjamin |  GBR | 44.85 Q | 0.170 | 
| 2 | 503 | Brandon Simpson |  JAM | 44.98 Q | 0.170 | 
| 3 | 680 | James Godday |  NGR | 45.30 q PB | 0.177 | 
| 4 | 87 | California Molefe |  BOT | 45.34 q NR | 0.182 | 
| 5 | 869 | Pierre Lavanchy |  SUI | 45.79 q | 0.157 | 
| 6 | 170 | Željko Vincek |  CRO | 46.03 | 0.191 | 
| 7 | 514 | Abdesalem Khalifeh Bajes Al-Hajjaj |  JOR | 48.89 | 0.194 | 
| 8 | 655 | Florent Battistel |  MON | 50.54 | 0.178 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1039 | Jeremy Wariner |  USA | 45.24 Q | 0.134 | 
| 2 | 356 | Robert Tobin |  GBR | 45.41 Q | 0.157 | 
| 3 | 1055 | Young Talkmore Nyongani |  ZIM | 45.55 q | 0.177 | 
| 4 | 584 | Hamdan Odha Al-Bishi |  KSA | 45.88 q | 0.145 | 
| 5 | 63 | Cedric van Branteghem |  BEL | 46.42 | 0.152 | 
| 6 | 641 | Alejandro Manuel Cárdenas |  MEX | 46.73 SB | 0.151 | 
| 7 | 759 | Isaac Yaya |  PYF | 47.75 | 0.170 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 34 | John Steffensen |  AUS | 45.62 Q | 0.147 | 
| 2 | 133 | Tyler Christopher |  CAN | 45.66 Q | 0.164 | 
| 3 | 203 | Arismendy Peguero |  DOM | 45.80 q SB | 0.237 | 
| 4 | 659 | Eric Milazar |  MRI | 45.91 | 0.158 | 
| 5 | 45 | Andrae Williams |  BAH | 46.49 | 0.182 | 
| 6 | 387 | Simon Kirch |  GER | 47.45 | 0.132 | 
| 7 | 1052 | Saeed Al-Adhreai |  YEM | 49.74 | 0.161 | 
| 52 | Tawhid Tawhidul Islam |  BAN | DQ | 0.249 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1023 | Andrew Rock |  USA | 44.98 Q | 0.241 | 
| 2 | 49 | Chris Brown |  BAH | 45.20 Q | 0.175 | 
| 3 | 455 | Andrea Barberi |  ITA | 45.70 q PB | 0.162 | 
| 4 | 928 | Sofiane Labidi |  TUN | 45.71 q | 0.149 | 
| 5 | 530 | Mitsuhiro Sato |  JPN | 45.78 q SB | 0.149 | 
| 6 | 101 | Anderson Jorge dos Santos |  BRA | 46.32 | 0.206 | 
| 7 | 913 | Cheng-Kang Chung |  TPE | 47.85 PB | 0.240 | 
| 8 | 855 | Glauco Martini |  SMR | 51.48 | 0.237 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 492 | Michael Blackwood |  JAM | 45.58 Q | 0.213 | 
| 2 | 206 | Carlos Santa |  DOM | 45.63 Q | 0.155 | 
| 3 | 420 | Alleyne Francique |  GRN | 45.77 q | 0.195 | 
| 4 | 728 | Marcin Marciniszyn |  POL | 45.97 | 0.211 | 
| 5 | 915 | Damion Barry |  TTO | 46.20 | 0.216 | 
| 6 | 167 | Nery Brenes |  CRC | 47.11 | 0.188 | 
| 7 | 41 | Ibrahim Ahmadov |  AZE | 48.51 | 0.141 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 161 | Gary Kikaya |  COD | 45.88 Q | 0.160 | 
| 2 | 504 | Lansford Spence |  JAM | 46.21 Q | 0.198 | 
| 3 | 788 | Ofentse Mogawane |  RSA | 46.80 | 0.249 | 
| 4 | 53 | Wilan Louis |  BAR | 46.93 | 0.208 | 
| 5 | 857 | Prasanna Sampath Amarasekara |  SRI | 47.11 | 0.270 | 
| 6 | 856 | Chris Meke Walasi |  SOL | 49.47 | 0.175 | 
| 688 | Saul Welgopwa |  NGR | DQ | 0.162 | |
| 661 | Boubou Gandéga |  MTN | DQ | 0.180 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1042 | Darold Williamson |  USA | 45.97 Q | 0.201 | 
| 2 | 861 | Nagmeldin Ali Abubakr |  SUD | 46.02 Q | 0.173 | 
| 3 | 344 | Malachi Davis |  GBR | 46.14 | 0.196 | 
| 4 | 920 | Ato Stephens |  TTO | 46.28 | 0.155 | 
| 5 | 312 | Leslie Djhone |  FRA | 46.57 | 0.159 | 
| 6 | 202 | Chris Lloyd |  DMA | 47.13 | 0.256 | 
| 7 | 1050 | Moses Kamut |  VAN | 48.63 | 0.223 |