He finished in 44.84 seconds.

Thus, Chalmers set a new world record at a distance, surpassing the achievement of the Frenchman Amory Leveaux (44.94).

The second place was taken by Russian Vladimir Morozov (46.32), and his compatriot Kliment Kolesnikov (46.35) closed the top three. 

Earlier, Russian swimmer Pavel Samusenko won gold in the 50m backstroke at the KM stage in Kazan.