Kelsey-Lee Barber's approach to the Olympic women's javelin final will be a pretty straightforward one - start off the same way that she finished the qualifying round.

Barber has a deserved reputation as a clutch thrower on the sport's biggest stages.

She became Australia's only gold medallist at the 2019 world championships in Doha by moving all the way from fourth place to first with a massive final-round effort of 66.56m.

The 29-year-old was at it again in the Olympic javelin qualifying competition on Wednesday.

Staring down the barrel of an ignominious early exit after two poor throws in what to date has been a mediocre year, Barber smashed out a 62.59m effort which saw her advance to the final in third spot overall.

The last throw of the dice approach makes for exciting viewing.

But Barber and her coach and husband Mike Barber know full well there's a better way.

"I feel really clear about what I need to do now and how I go about that, so that's the energy I want from the very beginning," Barber told AAP.

"I can only push forward from there.

"In the first two rounds of qualifying I was just in a really comfortable place in how I was setting up to throw.

"But I forgot to attack it, I forgot to use that energy and work from the ground up.

"I was too relaxed, too comfortable and too controlled.

"In the simplest form I just forgot how to throw the javelin."

Poland's Maria Andrejczyk - who tops the 2021 world list with a massive throw of 71.40m back in May - will be the deserved gold-medal favourite in Friday's final in Tokyo.

But in 2019 world champion Barber, reigning Commonwealth Games gold medallist Kathryn Mitchell and Mackenzie Little - who smashed her PB in the qualifying round - Australia will have a full complement of three for the first time in any Olympic throwing final.

"It speaks values to our throwing community back home and what we've been able to achieve as a country," said Barber.

"Three different coaches producing three diferent female athletes in a final is unbelievable and it makes me super proud to be part of that Aussie group making history."