Australian swimmer James Magnussen earned a shot at history and left his rivals thinking

about silver after storming into Thursday night's 100m freestyle final

at the world swimming championships in Shanghai.

Magnussen, 20,

cemented his status as the event's favourite by clocking 47.90 seconds

in the semi-finals, the second sub-48 second swim of his career, to

qualify well ahead of a class field including American Nathan Adrian

(48.05), Canada's Brent Hayden (48.30) and reigning champion Cesar Cielo

(48.34) of Brazil.

No Australian man has won the 100m freestyle

since the world championships were first held in 1973, while the last

Australian Olympic champion event was Michael Wenden in 1968.

And Magnussen is confident he can make history.

"I

didn't feel as sharp as I did the other night for the relay, I haven't

had a lot of sleep in the last few days because my mind's just been

ticking over," said Magnussen, who turned in sixth before producing his

trademark powerful finish.

"So to get that one out of the way and get another sub-48 is a big confidence booster for tomorrow night.

"I

wasn't as confident as I probably should have been going into tonight

but after another sub 48 I'm feeling pretty good about myself and

feeling like I can go a bit faster again."

Magnussen said the key for the biggest night of his short career would be keeping his mindset that way.

"I think it's just the mindspace for me, I'm a confidence swimmer … when I'm confident crazy things happen," he said.

Fellow Australian James Roberts (48.49) clocked a PB in the semi, but just missed the final.

Magnussen

exploded into favouritism for the 100m title with his blistering

47.49-second lead-out performance in Australia's 4x100m freestyle relay

win, the fastest ever 100m swim without a "super suit".

The

performance had coaches from around the globe stunned and reigning world

champion and record holder Cielo virtually conceding defeat ahead of

Thursday's final.

"I don't know what I can do if he does it (47.49) again. I don't think anybody (can catch him)," Cielo said after the heats.

Port

Macquarie-born Magnussen rose to prominence at the national titles in

April, with his win in the 100m earning an individual swim in China

after having travelled as a relay swimmer with the national squad last

year.

But his improvement in China has his coach Brant Best

surprised, especially after the swimmer was floored by a bout of

pneumonia prior to the meet.

Best, who started coaching the

swimmer 18 months ago, said the challenge would be for Magnussen to not

get ahead of himself but said he was a "natural competitor".

"He loves to win," Best said on Wednesday.

"(He's

turned) around from a country boy who was fairly laconic and kind of

did what he needed to do to get by, to just wanting to do everything and

tick every box to go fast."