Titmus hit the wall at Australia's Olympic trials in Brisbane ahead of O'Callaghan, who also went under her previous world record of 1:52.85, finishing in 1:52.48.
Australia's Titmus shatters 200m freestyle world record
Olympic champion Ariarne Titmus shattered fellow Australian Mollie O'Callaghan's 200m freestyle world record Wednesday, touching in 1min 52.23secs, with the Paris Games just weeks away.