By Drazen Jorgic RIO DE JANEIRO, Aug 10 - Australia's teenage Olympic champion Kyle Chalmers said he was bowled over by a video from NBA player Kevin Durant and a letter of support from Ian Thorpe before his sensational victory in the 100 metres freestyle on Wednesday. Chalmers, 18, was seventh at the 50m mark but mounted a stunning final length swim to snatch gold in the sport's blue riband event. After his victory, basketball fan Chalmers revealed an accidental encounter with Durant in Rio de Janeiro led to him receiving a personal video of support from the Golden State Warriors player.