Rio de Janeiro: Kyle Chalmers has stunned the swimming world. The Adelaide 18-year-old has come from the clouds to upset the superstars of men's sprinting and take a famous gold medal in the 100m freestyle final.

With American Nathan Adrian and Australia's Cameron McEvoy the overwhelming favourites, Chalmers surged through the field to win the first gold medal for Australia in this event since Michael Wenden in 1968.

Cameron McEvoy congratulates Kyle Chalmers after he won Rio gold. Credit:Joe Armao

McEvoy was never in the race, finishing seventh, while Chalmers was right in touch with the field at the turn and finished over the top of them to complete a meteoric rise to the top of men's sprinting in a time of 47.58.

The pre-race favourite, McEvoy, was gracious in defeat, heaping praise on his teenage teammate. "To have an Olympic champion, that's bloody wonderful," he said of Chalmers.