World champion James Magnussen delivered on his promise to make a statement to his international rivals, improving on the fastest ever 100m freestyle time in a textile suit in a stunning victory at the Olympic trials in Adelaide.

Magnussen, 20, clocked 47.10 seconds to improve on his 47.49-second swim at last year's world championships in Shanghai and further enhance his status as the hottest of gold medal favourites for London.

While he fell just shy of breaking Brazilian Cesar Cielo's world record of 46.91 seconds, his message to the chasing pack of sprinters across the world was loud and clear after the race.

"Brace yourselves," he said. "... I feel pretty confident after that swim but I'm certainly not going to rest on my laurels.

"I'm going to be doing everything in my power to break that world record because I do want to be considered the fastest man in history."

James Roberts, born on the same day as Magnussen, became the second fastest man post-suits with a brilliant 47.63 to secure the second individual berth in London.

Matt Targett (47.63), Eamon Sullivan (48.53), Cameron McEvoy (48.58) and Tommaso D'Orsogna (48.64) rounded out the top six to be considered for 4x100m relay selection with Matt Abood (48.81) and Kyle Richardson (48.95) missing out.

Magnussen said he had decided to set out to break Cielo's world record set in a supersuit at the farcical 2009 world titles in Rome.

Some predicted that record could stand for a decade after polyurethane swimsuits were banned following that meet but Magnussen now seems destined to break it in London.

"... It was a really exciting race and I executed everything pretty close to the way I wanted to," said Magnussen, who clocked an incredible 22.68 for his first 50m.

"Not quite good enough tonight but I'll definitely give that world record another crack.

"I backed myself tonight, really went after it and really felt it in that last 10 metres."

Magnussen's time in the post-suits era stands miles ahead of the rest of the chasing international pack led by Cielo (47.84) and Canada's Brent Hayden (47.95).

Magnussen credited Roberts with pushing him all the way, as the latter clocked the exact same time Magnussen did in winning the world title in China.

Roberts' swim meant he emerged as a genuine medal contender in London and helped ease his pain after he was the unlucky man to miss out in Australia's victorious 4x100m freestyle relay team in Shanghai.

"I'm over the moon. World championships for me was my first major event, it was a huge learning curve for me and I've taken what I learned there back into training," Roberts said.

"... I was in a little bit of a shock to see how far under 48 I went but it's a great feeling."

Magnussen said the men's relay team was looking even better after Roberts' swim.

"If the Olympics were going to be tomorrow you'd have to say that relay team was pretty bulletproof," Magnussen said.

"The rest of the world can try and catch us, I guess that's all they've got to do isn't it?"

Michael Klim, who famously helped win Australia's last Olympic gold medal in the event, alongside Ian Thorpe, Chris Fydler and Ashley Callus at the Sydney 2000 Games is tipping Australia's men will easily end a 12-year drought in the event by overpowering the Americans in London.

"Australia just assembled the best 4x100 ever no one will get close forget the guitars these boys will bring home the gold and create history," Klim said on Twitter, referring to the Americans' boast they would smash the Australians "like guitars" prior to the final in Sydney.

Meanwhile comeback swimmer Libby Trickett moved to the verge of sealing a return to the team in London, as she comfortably progressed to Tuesday night's 100m freestyle final.

Cate Campbell (53.84) was fastest qualifier ahead of Melanie Schlanger (53.91) and Alicia Coutts (54.11), with Trickett fifth fastest in 54.19.

Trickett will need at least a top six finish in the decider to be considered for selection as a relay swimmer.

"It's going to be a tough race, but I so want to make the Olympic team now I'm this close," she said.

Dual Olympian Jessicah Schipper booked a second individual swim in London after claiming the national 200m butterfly title for an eighth consecutive year.

Schipper (2:06.93) led from the start and could not be headed, comfortably touching ahead of Samantha Hamill (2:06.93), who is now off to her second Olympics after scraping through under the A-qualifying time by 0.03 seconds.

In a night for the favourites, Olympic silver medallist Brenton Rickard claimed his fifth national 200m breaststroke title in a time of 2:11.03, adding a second individual swim to his Olympic schedule following his selection in the 100m event on Friday.

Rickard, who placed second over 200m at the Beijing Olympics, took control of the race at the 50-metre mark from Jeremy Meyer (2:12.76), who narrowly beat Nicholas Schafer (2:12.96) to the wall for second place.

Meyer, who finished 1.02 seconds outside the A-qualifying mark, must now wait until Thursday to discover whether he will be selected for his first Olympic squad.

Sally Foster has booked Lane 4 for the final of the 200m breaststroke after recording a semi-final time of 2:27.92. Foster, who led the quicker of the two semi-finals, finished ahead of 16-year-old young gun Taylor McKeown and world championship silver medallist Sarah Katsoulis who finished equal second in 2:28.61. Lurking in the shadows is three-time Olympic gold medallist Leisel Jones, who won the other semi-final and claimed the fifth quickest time of 2:29.21.

Victorian teammates Matson Lawson (1:58.53) and Josh Beaver (1:59.03) have recorded the two quickest times in the men’s 200m backstroke leading into tomorrow night’s final. Australian record holder Ashley Delaney was only a fraction off the pace in 1:59.20 with hometown hero Hayden Stoeckel (1:59.53) also making it through in an effort to secure his fourth Australian title in the event.

Commonwealth Games representative Jayden Hadler (1:59.69) will be the one to catch in the final of the men’s 200m IM after posting an A-qualifying time in his semi-final. Daniel Tranter (1:59.88), who is already off to London following his second placing in the 400m IM, also went under the two-minute barrier to qualify second. Commonwealth Games relay gold medallist Thomas Fraser-Homes (2:00.12) clocked the third fastest time ahead of triple Junior Pan Pacific gold medallist Kenneth To (2:00.87). Commonwealth record holder for this event, Leith Brodie (2:02.47), and dual Olympian Travis Nederpelt (2:02.53) will also progress to tomorrow night’s final.

AAP and Swimming Australia