| POS | ATHLETE | COUNTRY | MARK | Reaction Time |
|---|---|---|---|---|
| 1 | Germany U20 |
GER
|
43.80 Q WU20L | 0.154 |
| 2 | Great Britain & NI U20 |
GBR
|
44.84 Q | 0.138 |
| 3 | Switzerland U20 |
SUI
|
45.01 Q SB | 0.209 |
| 4 | Australia U20 |
AUS
|
45.26 q SB | 0.180 |
| 5 | Canada U20 |
CAN
|
45.68 SB | 0.172 |
| PR of China U20 |
CHN
|
DQ | 0.161 | |
| United States U20 |
USA
|
DQ | 0.144 |
| POS | ATHLETE | COUNTRY | MARK | Reaction Time |
|---|---|---|---|---|
| 1 | Ireland U20 |
IRL
|
44.27 Q | 0.155 |
| 2 | Italy U20 |
ITA
|
44.52 Q | 0.174 |
| 3 | France U20 |
FRA
|
44.80 Q SB | 0.165 |
| 4 | Poland U20 |
POL
|
45.19 q | 0.150 |
| 5 | Brazil U20 |
BRA
|
45.28 SB | 0.131 |
| 6 | Austria U20 |
AUT
|
45.99 | 0.173 |
| Jamaica U20 |
JAM
|
DQ | 0.195 |