China's Sun Yang has stormed to victory in the 800m freestyle final at the World Championships in Kazan.
The controversial swimmer, who won gold in the 400m freestyle earlier in the week, paced himself well throughout the race.
At the final turn, Sun moved to second in the field before charging down 25m to touch the wall first in 7:39.96.
Great Britain's Stephen Milne, who qualified third fastest for the final, failed to keep up with the leaders, but clocked 7:49.86 to finish seventh.
