The 2008 Olympic champion LaShawn Merritt topped the lists for the season as the only man under 44 seconds.

At that competition the trio had all run under 44 seconds for medals (a first for the sport) and were the principal challengers to the Olympic title.

The 2016 World Indoor Champion Pavel Maslák, David Verburg and Rafał Omelko qualified as fastest losers.

[5] In the semi-finals, James had a season's best time of 44.02 to win the round nearly two tenths ahead of Merritt.

Fastest loser qualifiers Karabo Sibanda, Matthew Hudson-Smith and Ali Khamis all set personal bests.

In the home straight van Niekerk increased his lead while James overtook Merritt, finishing second and third.

The top six finishers from 2012 (in order: Kirani James of Grenada, Luguelín Santos of the Dominican Republic, Lalonde Gordon of Trinidad and Tobago, Chris Brown of the Bahamas, and Kevin Borlée and Jonathan Borlée of Belgium) returned.

LaShawn Merritt of the United States, 2008 gold medalist who was injured and could not finish his heat in 2012, also returned.

The top two runners in each semifinal heat and the next two fastest overall advanced, making an eight-man final.