Kyle Chalmers has secured his shot at defending his Olympic 100-metre freestyle title with victory at Australia’s selection trials.

Chalmers triumphed in Tuesday night’s final in Adelaide, ensuring his entry in the blue riband event at next month’s Tokyo Games.

Chalmers, who rose to fame with his surprise gold medal at the 2016 Olympics, adds the 100m to his victory in the 200m freestyle at the trials on Sunday night.

In his pet event over the shorter distance, the 22-year-old clocked 47.59 seconds to win from Matt Temple (48.32s).

Earlier, Zac Stubblety-Cook set a 200m breaststroke Commonwealth record as his rival Matt Wilson’s Olympic heartbreak continued.

Stubblety-Cook produced a late surge to win but second-placed Wilson finished 0.24 seconds outside the qualifying time specified by Swimming Australia.

Wilson’s dejection mirrors 2016, when he won the event at trials but was 0.26s short of the qualifying mark and missed out on the Rio Olympics.

“It’s pretty gut-wrenching seeing that,” Stubblety-Cook said of his rival.

“It’s just the nature of the sport. It’s tough, there’s no other word for it.”

Wilson’s Olympic ambitions now rest with a discretionary selection - and he also lost his Commonwealth record to Stubblety-Cook.

The 22-year-old winner’s time of two minutes 06.28 seconds was only 0.16s from the world record held by Russian Anton Chupkov and the second-fastest ever.

“It doesn’t feel real yet,” Stubblety-Cook said.

“It’s exciting. I have just got to take it in my stride.”

In the women’s 200m butterfly, WA’s Brianna Throssell booked her berth on the team for Tokyo with victory ahead of 17-year-old Elizabeth Dekkers, who finished outside the qualifying mark.