McKeown became the first Australian in Olympic history to clinch the ‘double-double’ — winning four individual gold medals — after triumphing in the women’s 200m backstroke in Paris.

McKeown is also the first swimmer to successfully defend 100m and 200m backstroke titles in Olympic history.

“What a champion she is,” cried Nine commentator Mat Thompson.

“Fraser, Thorpe, Rose, Hackett, Perkins, Jones. The best of the best. None have achieved this. The ‘double double’ is complete for individual gold medals.”

Olympic legend Ian Thorpe, also commentating for Channel Nine, said McKeown was a “global superstar”.

“She’s created Australian history, let’s celebrate her Australia,” said Thorpe.

“I don’t think people realise how significant what she’s just achieved is. She’s done the double-double.”

Compatriot Cameron McEvoy won the men’s 50m freestyle gold just 10 minutes before McKeown on Saturday morning (AEDT).

It was Australia’s first medal of any colour in the men’s 50m freestyle since the event was introduced at Seoul 1988.

McEvoy’s victory is his first Olympic gold. Aged 30 and at his fourth Olympics, McEvoy is the oldest Australian swimmer to capture gold.

He triumphed in 21.25 seconds in the one-lap dash ahead of Great Britain’s Ben Proud (21.30) and Frenchman Florent Manaudou (21.56).

“We waited so long to see this athlete be the athlete that he actually is,” said Thorpe.

“He has been able to deliver what he’s always wanted to accomplish, but he’s always wanted to do. And what we’ve always known he could do.”

Speaking poolside after his achievement, McEvoy described the moment as “pure joy”.

McKeown now has five golds in her Olympic career, with a women’s 4x100m medley victory at the Tokyo Games three years ago among her collection.

Fellow swimmer Emma McKeon holds the Australian record for most Olympic golds — she has won six, with four coming in relays.

McKeown has the opportunity to strike more gold in Paris.

She will race in the semi-finals of the 200m individual medley later Friday night and boasts the event’s fastest time in the world this year.

McKeown defended her 100m backstroke crown on Wednesday morning (AEDT) and her victory over the longer distance gives Australia’s swim team a seventh gold medal in Paris.

Other Dolphins winners in the French capital are Ariarne Titmus (women’s 400m freestyle), the women’s 4x100m freestyle relay team, Mollie O’Callaghan (women’s 200m freestyle), the women’s 4x200m freestyle team and McEvoy.

McEvoy’s victory helps erase his lingering disappointment from the Rio Games eight years ago when he entered the 100m freestyle medal race as hot favourite but finished seventh in a final won by compatriot Kyle Chalmers.

McEvoy took an extended break from the swimming after the Tokyo Olympics three years ago when disillusioned with the sport.

But he returned to the pool with a self-styled revolutionary training regime.

McEvoy, a physics student nicknamed The Professor who aspires to be an astronaut, bases his training around technical minutia in the water.

But outside the pool, he retains fitness with activities such as calisthenics and rock climbing rather than swimming endless laps.

– with AAP