| Order / Lane | ATHLETE | COUNTRY | PB | SB 2018 | 
|---|---|---|---|---|
| 2 | Germany U20 | 
                             
                            GER
                         | 
                            43.27 | 44.42 | 
| 3 | Great Britain & NI U20 | 
                             
                            GBR
                         | 
                            43.81 | 44.57 | 
| 4 | Australia U20 | 
                             
                            AUS
                         | 
                            44.86 | |
| 5 | Switzerland U20 | 
                             
                            SUI
                         | 
                            44.61 | 45.36 | 
| 6 | United States U20 | 
                             
                            USA
                         | 
                            43.29 | |
| 7 | Canada U20 | 
                             
                            CAN
                         | 
                            44.77 | |
| 8 | PR of China U20 | 
                             
                            CHN
                         | 
                            44.75 | 45.06 | 
| Order / Lane | ATHLETE | COUNTRY | PB | SB 2018 | 
|---|---|---|---|---|
| 2 | France U20 | 
                             
                            FRA
                         | 
                            43.68 | 45.72 | 
| 3 | Brazil U20 | 
                             
                            BRA
                         | 
                            43.98 | |
| 4 | Ireland U20 | 
                             
                            IRL
                         | 
                            44.15 | 44.15 | 
| 5 | Italy U20 | 
                             
                            ITA
                         | 
                            44.52 | |
| 6 | Austria U20 | 
                             
                            AUT
                         | 
                            45.71 | 45.77 | 
| 7 | Jamaica U20 | 
                             
                            JAM
                         | 
                            43.40 | 44.73 | 
| 8 | Poland U20 | 
                             
                            POL
                         | 
                            43.79 | 45.11 |