BELLA Pasquali and the Australian U20 mixed 4x400m team have conquered the world after winning gold Wednesday morning.

Qualifying fastest overnight in Lima, Peru, the Australians made up of Bella, Jordan Gilbert, Jack Deguara and Sophia Gregorevic dominated the field to smash their own U20 Oceanic record from their heat run, finishing in 3:19.27 in the final.

Running second, Bella was handed the baton from Gilbert in a tight opening to the race and was able to put a gap between the field as she reached the back straight, coming home in signature fashion to set up a lead Australia would never relinquish.

Her split of 52.43sec was the fastest run by any woman in the relay final.

In comparison, Bella's personal best from a standing start stands at 53.89sec.

Fellow Victorian Gregorevic was tasked with the final leg of the race and held her nerves to come home with a comfortable win, as Poland (3:20.44) and China (3:21.27) took out the remaining podium positions.

It was first medal Australia has won at the championships following the conclusion of day one.

Watching on from home, mum Anna Pasquali said she had been overwhelmed by the support and love shown by the community in the aftermath of the 17-year-old’s golden run.

“It was a really big surprise, I was rapt they made it to the final let alone win,” she said.

“I’ve had heaps of texts and calls, the support from the whole town has been wonderful.”

Dad Wally and sister Sophia were in the stands at Peru cheering Bella home along with the rest of the Australian junior team.

Anna said Bella had been blessed with the backing of her school Galen Catholic College who gave her a guard of honour on her way out and coach Jason Boulton who had the athlete primed for the biggest run of her life so far.

Bella’s performance in the mixed relay will most likely see her lining up for the Australian women’s relay team in the 4x400.

Their heat ran from 2:30am AEDT overnight and with a performance like her mixed relay final split, the team could secure another shot at a medal at 9:30am Saturday morning.

You can watch Bella and all the action of the Junior World Championships via the link: https://worldathletics.org/competitions/world-athletics-u20-championships/lima24/where-to-watch?countryCode=AU.