Rio de Janeiro: The rivalry between Australian distance star Mack Horton and China's defending gold medallist Sun Yang just went to the next level, with Horton saying he has no 'time or respect for drug cheats' in the wake of a training run-in between the pair earlier in the week.

The 20-year-old Victorian looked strong as he cruised into the final of the 400m freestyle, qualifying second behind American Conor Dwyer, with Yang fourth quickest.

Keeping his cool: Mack Horton. Credit:Getty Images

But the final now stands to be electrifying after Horton called out Yang in no uncertain terms after his race following an incident between the pair at the training pool just days out from the Games.

Fairfax Media broke news that Yang had been taunting and splashing Horton, who ignored the gestures and continued with his training. The report was later described by state-run Chinese media as 'fake news'.