Australian Mollie O'Callaghan grabs gold from teammate Ariarne Titmus

(Photo credit: Grace Hollars-USA TODAY Sports)

PARIS -- Australia's red-headed rocket Mollie O'Callaghan upset teammate and defending champion Ariarne Titmus to claim gold in the women's 200 meters freestyle at the Paris Olympics on Monday.

O'Callaghan stopped the clock in an Olympic record 1:53.27 at La Defense Arena, 0.54 seconds ahead of Titmus, with Hong Kong's Siobhan Haughey taking bronze.

Only weeks after Titmus