| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 2190 | Njabulo MBATHA | 
                                         
                                        RSA
                                     | 
                                    49.90 Q | 0.161 | 
| 2 | 1790 | Sam LUNT | 
                                         
                                        GBR
                                     | 
                                    50.00 Q NU20R | 0.151 | 
| 3 | 1971 | Kyo KIKUTA | 
                                         
                                        JPN
                                     | 
                                    51.04 | 0.158 | 
| 4 | 2222 | Akalanka KUDA LIYANAGE | 
                                         
                                        SRI
                                     | 
                                    51.45 | 0.185 | 
| 5 | 2214 | Mitja ZUBIN | 
                                         
                                        SLO
                                     | 
                                    52.55 | 0.184 | 
| 6 | 1914 | Paolo BOLOGNESI | 
                                         
                                        ITA
                                     | 
                                    53.92 | 0.163 | 
| 7 | 2065 | Maximiliano NUÑEZ | 
                                         
                                        MEX
                                     | 
                                    57.96 | 0.142 | 
| 1698 | Joel VON DE AHÉ | 
                                         
                                        DEN
                                     | 
                                    DNS | 
| POS | BIB | ATHLETE | COUNTRY | MARK | ms* | Reaction Time | 
|---|---|---|---|---|---|---|
| 1 | 1757 | Antti SAINIO | 
                                         
                                        FIN
                                     | 
                                    49.36 Q WU20L | .351 | 0.172 | 
| 2 | 1681 | Michal RADA | 
                                         
                                        CZE
                                     | 
                                    49.36 Q WU20L | .352 | 0.163 | 
| 3 | 2340 | Vance NILSSON | 
                                         
                                        USA
                                     | 
                                    49.82 q | 0.212 | |
| 4 | 1709 | Joaquin ALONSO | 
                                         
                                        ESP
                                     | 
                                    50.22 q NU20R | 0.195 | |
| 5 | 1901 | Fintan DEWHIRST | 
                                         
                                        IRL
                                     | 
                                    51.65 | 0.165 | |
| 6 | 1900 | David DAVITT | 
                                         
                                        IRL
                                     | 
                                    51.93 | 0.157 | |
| 7 | 2014 | Ali Abdulfattah ALRUMAYH | 
                                         
                                        KSA
                                     | 
                                    52.25 PB | 0.175 | |
| 8 | 1963 | Trevoy SMITH | 
                                         
                                        JAM
                                     | 
                                    54.24 | 0.171 | 
ms - Milliseconds - shown when two or more competitors finish with the same time down to hundredths of a second
| POS | BIB | ATHLETE | COUNTRY | MARK | Reaction Time | 
|---|---|---|---|---|---|
| 1 | 1966 | Daniel WRIGHT | 
                                         
                                        JAM
                                     | 
                                    51.11 Q | 0.208 | 
| 2 | 1626 | Ramón FUENZALIDA | 
                                         
                                        CHI
                                     | 
                                    51.33 Q PB | 0.179 | 
| 3 | 1967 | Kairi GONDA | 
                                         
                                        JPN
                                     | 
                                    51.80 | 0.283 | 
| 4 | 2059 | Jose Eduardo AGUADO | 
                                         
                                        MEX
                                     | 
                                    52.57 | 0.137 | 
| 5 | 1584 | Lucas DE ALMEIDA | 
                                         
                                        BRA
                                     | 
                                    52.67 PB | 0.157 | 
| 6 | 2360 | Premier WYNN | 
                                         
                                        USA
                                     | 
                                    52.76 | 0.239 | 
| 7 | 2283 | Cheyne WEST | 
                                         
                                        TTO
                                     | 
                                    53.09 | 0.159 | 
| 8 | 1637 | Jingwei GUO | 
                                         
                                        CHN
                                     | 
                                    1:03.89 | 0.196 |