Brown crossed the line in the silver medal position, one minute and eight seconds behind eventual winner, Netherlands' Annemiek van Vleuten (30 minutes and 13.49 seconds).

The south-west export, who was making her Olympic debut in Tokyo, stopped the clock in 31 minutes and 22.22 seconds.

The 29-year-old was eventually passed by Switzerland's Marlen Reusser and Netherlands' Anna van der Breggen at the finish of the 22.1km course loop at Fuji International Speedway.

"You come across the line knowing there is still some fast riders coming in behind you, and it is seeded like that," Brown told Channel Seven after her ride.

"I was fifth favourite coming into the race and being on the hot seat is exciting but you know there is a chance you'll be kicked off so you are watching each rider come across the line and doing the maths.

"The great thing about this event is all you can do is ride your best it doesn't matter what anyone else is doing, it is just you and your machine.

"I rode to my best today and that got me in fourth position and I am proud of that."

Van der Breggen stopped the clock just seven seconds ahead of Brown to claim bronze. Reusser was a further five seconds ahead in silver.

Brown, who was the 20th rider to head down the start ramp, was 6.29 seconds behind Van Vleuten at the first time check at 9.7km into the time trial.

World champion van der Breggen was in third, 18.95 seconds behind her Dutch teammate. Reusser was fifth at the first check.

At the second check Van Vleuten was still the fastest with Brown 28.01 seconds back in second after 15km. Van der Breggen was in third at the final check.

"There were two time checks and coming through both of those I was second behind Annemiek so I was pretty confident I was doing well," Brown said.

"But those last five Ks were brutal and I was on my limit so I think I lost a little bit of time in the run to the line."

Fellow Australian Sarah Gigante finished in 11^th two minutes and 48 seconds behind Van Vleuten, who won silver in the road race on Sunday.

Earlier in the event, Gigante recorded the fastest time, crossing the line in 33 minutes and 1.60 seconds.

France's Juliette Labous eventually forced Gigante out of the hot seat before Van Vleuten powered into the gold medal position.

Brown, who joined the sport six years ago, said she was eager to continue her rise.

"It is pretty phenomenal and I pinch myself seeing how quickly I have got to this (point)," she said.

"There is more to be done and I can keep improving on this discipline which is really cool."

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