Pos  | Rank  | Heat  | Bib | Athlete | Mark  | Details  | Reaction Time  | |
|---|---|---|---|---|---|---|---|---|
1  | 1  | 3  | 2742 | NOR | 47.09   | Q  | 0.162  | |
2  | 1  | 2  | 2971 | USA | 47.24   | Q  | 0.169  | |
3  | 2  | 3  | 2537 | JAM | 47.34 WU20R  | Q  | 0.198  | |
4  | 3  | 3  | 2968 | USA | 47.38 PB  | q  | 0.187  | |
5  | 2  | 2  | 2113 | BRA | 47.38 SB  | Q  | 0.182  | |
6  | 1  | 1  | 2526 | IVB | 47.72   | Q  | 0.168  | |
7  | 2  | 1  | 2261 | EST | 48.30   | Q  | 0.180  | |
8  | 4  | 3  | 2362 | GER | 48.39   | q  | 0.179  | |
9  | 5  | 3  | 2515 | ITA | 48.43   | 0.152  | ||
10  | 3  | 1  | 2965 | USA | 48.44   | 0.152  | ||
11  | 3  | 2  | 2331 | FRA | 48.48   | 0.194  | ||
12  | 4  | 1  | 2546 | JAM | 48.49   | 0.150  | ||
13  | 4  | 2  | 2578 | JPN | 48.58 PB  | 0.144  | ||
14  | 6  | 3  | 2929 | TUR | 48.66 SB  | 0.220  | ||
15  | 5  | 2  | 2363 | GER | 48.71 PB  | 0.196  | ||
16  | 7  | 3  | 2310 | FRA | 48.83   | 0.176  | ||
17  | 5  | 1  | 2090 | BEL | 48.94   | 0.205  | ||
18  | 6  | 1  | 2721 | NGR | 49.22   | 0.209  | ||
19  | 8  | 3  | 2189 | CRC | 49.31   | 0.169  | ||
20  | 6  | 2  | 2623 | KEN | 49.40   | 0.196  | ||
21  | 7  | 1  | 2813 | QAT | 49.50   | 0.172  | ||
22  | 7  | 2  | 2171 | CHN | 49.57   | 0.189  | ||
23  | 8  | 2  | 2867 | SUI | 49.75   | 0.175  | ||
1  | 2504 | ITA | DQ   | -0.017  |