Australia's Kyle Chalmers has begun the defence of his men's Olympic 100 metres freestyle title in impressive fashion, qualifying third fastest for the semi-finals in Tokyo.
The 2016 Rio gold medallist will compete in the semi-finals on Wednesday morning, while he is also set to contest the 4x200m freestyle final as a member of Australia's squad in the same session.
Alex Graham, Mack Horton, Elijah Winnington and Zac Incerti qualified second fastest behind hot favourite Great Britain, with Chalmers and Thomas Neill expected to replace two of the heat swimmers in the final.
In other Australian results on Tuesday night, Zac Stubblety-Cook qualified equal fastest for the men's 200m breaststroke semi-finals, with Matthew Wilson also advancing to the final 16.
Jack McLoughlin, who has already claimed a silver medal in Tokyo, reached the men's 800m freestyle final and Brianna Throssell went through to the women's 200m butterfly semi-finals as the ninth-fastest qualifier with a heat time of 2:09.34.
Chalmers won his 100m freestyle heat in a solid time of 47.77 seconds, with only Italian Thomas Ceccon (47.71) and two-time world champion Caeleb Dressel (47.73) of the United States swimming faster in the heats.
However, Chalmers' Australian teammate Cameron McEvoy did not advance to the semi-finals after placing seventh in his heat with a time of 48.72.
"It's a good confidence booster," Chalmers told Channel Seven after his heat swim.
"Seven months ago I had shoulder surgery, so [I'm] still kind of coming back and trying to get under the 48-second mark, so to do that in the heat is really nice."
Chalmers also produced a blistering anchor leg of 46.44 to help Australia claim bronze in the men's 4x100m freestyle on Monday.
On Tuesday night, the 23-year-old worked his way into his 100m freestyle heat before finishing over the top of the field in the second half of the race.
"I felt really relaxed today," Chalmers said.
Dressel has already won one gold in Tokyo, having been a member of the victorious US men's 4x100m freestyle team.
He has claimed the past two world championships in the 100m freestyle, beating Chalmers by 0.12 at the 2019 edition in Gwangju.
Aussie breaststrokers through to semis
Brisbane-based Stubblety-Cook dead-heated with Dutchman Arno Kamminga in their heat in 2:07.37, the fastest time of the opening preliminaries.
The Australian was fourth in the 200m breaststroke at the 2019 world championships.
Wilson, a silver medallist in the event at the world titles two years ago, also qualified for the Tokyo semi-finals.
Wilson, a former world record holder in the event, earned selection in Australia's Olympic squad on compassionate grounds and swam a time of 2:09.29 to finish fifth in his heat.
McLoughlin was third in his heat of the men's 800m freestyle, which is making its Olympic debut in Tokyo.
The 400m freestyle silver medallist stopped the clock in the longer event in 7:46.94 to be sixth fastest for Thursday morning's final.
Ukrainian Mykhailo Romanchuk was the fastest in the heats with an Olympic record of 7:41.28.
