| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 889 | Young Talkmore Nyongani |  ZIM | 46.15 Q | 0.174 | 
| 2 | 464 | Jermaine Gonzales |  JAM | 46.17 Q | 0.192 | 
| 3 | 669 | Piotr Zrada |  POL | 46.47 q PB | 0.127 | 
| 4 | 434 | David McCarthy |  IRL | 46.77 q | 0.149 | 
| 5 | 874 | Luis Luna |  VEN | 46.93 | 0.146 | 
| 6 | 32 | Keith Sheehy |  AUS | 47.68 | 0.182 | 
| 619 | Robert Lathouwers |  NED | DQ | 0.219 | |
| 551 | Mohammed Al-Mowallad |  KSA | DNF | 0.174 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 839 | Jonathan Fortenberry |  USA | 46.16 Q | 0.161 | 
| 2 | 74 | Wilan Louis |  BAR | 46.26 Q NJ | 0.171 | 
| 3 | 698 | Florin Suciu |  ROU | 47.09 | 0.289 | 
| 4 | 709 | Shaine Morrison |  RSA | 47.52 | 0.136 | 
| 5 | 108 | Diego Venâncio |  BRA | 47.57 | 0.176 | 
| 6 | 583 | Hicham Chliyeh |  MAR | 47.66 | 0.208 | 
| 7 | 351 | Kamghe Gaba |  GER | 47.67 | 0.189 | 
| 8 | 137 | Ryan Therrien |  CAN | 48.58 | 0.255 | 
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 860 | Darold Williamson |  USA | 46.31 Q | 0.181 | 
| 2 | 102 | LuÃs Ambrosio |  BRA | 46.61 Q PB | 0.157 | 
| 3 | 584 | Abdellatif El Ghazaoui |  MAR | 46.92 | 0.153 | 
| 4 | 308 | Brice Panel |  FRA | 47.20 | 0.162 | 
| 5 | 466 | Yhann Plummer |  JAM | 47.55 | 0.180 | 
| 6 | 455 | Jacopo Marin |  ITA | 47.71 | 0.188 | 
| 7 | 390 | DimÃtrios Grávalos |  GRE | 47.83 | 0.147 | 
| 8 | 31 | Courtney McLeod |  AUS | 48.24 | 0.161 |