O'Callaghan won in a new Olympic record time of 1min 53.27secs, with compatriot Titmus 0.54 seconds behind and Hong Kong's Siobhan Haughey taking the bronze
O'Callaghan won in a new Olympic record time of 1min 53.27secs, with compatriot Titmus 0.54 seconds behind and Hong Kong's Siobhan Haughey taking the bronze