Portugal Colonial - Titmus sets up Australian 200m freestyle showdown at Commonwealths

Elsewhere on the first day of sporting action in Birmingham, Zac Stubblety-Cook underlined Australia's power in the pool by topping the times in the 200m breaststroke heats.

Titmus clocked 1min 55.68secs at the Sandwell Aquatics Centre, nearly a second clear of 18-year-old O"Callaghan, who won six medals at the recent world championships in Budapest.

Titmus, who won 200m and 400m freestyle gold at last year's Tokyo Olympics, broke the 400m world record at the Australian championships in May.

The 21-year-old, who chose to skip the world championships in Hungary, suffered a bout of coronavirus last month but said she had no excuses.

"Everyone has gone through Covid, it is what it is," she said after her heat on Friday. "It took me a few weeks until I really felt like myself again.

"But no excuses, Covid is in the world and everyone is dealing with it so I can't let it affect me."

Stubblety-Cook timed 2:09.88 in his men's 200m breaststroke heat.

South Africa's Chad le Clos -- seeking to equal the all-time record of 18 Commonwealth medals -- finished eighth-quickest in the men's 50m butterfly heats.

Canada's 15-year-old star Summer McIntosh qualified for the final of the women's 400m individual medley nearly five seconds faster than the next-quickest swimmer.

Nogueira--PC