Ipswich's Mollie O'Callaghan has stunned the swimming world claiming an upset gold medal win in the 100 metres freestyle at the Commonwealth Games against her more fancied Aussie rivals.

The 18-year-old defeated fellow Aussies Shayna Jack and the favourite, Emma McKeon, who claimed silver and bronze respectively.

O'Callaghan came from fourth place at the turn to win the race in a PB time of 52.63.

O'Callaghan's old school St Peters Lutheran College at Springfield has congratulated her for the win.

 

Image: AP/AAP