Whiley defeated a top field to win the ​Castlemaine NAB 500 open 5km racewalk  Castlemaine Botanical Gardens​ on April 9.

The field for the handicap race included Rio Olympian Rhydian Cowley.

Fiji national Pramesh Prasad was second, one hundredth of a second ahead of Cowley.

Prasad is in line to represent Fiji at the 2018 Gold Coast Commonwealth Games. 

Cowley is representing Australia in China this week and also at the World Championships in London in August.

Whiley, 21, a former top junior, not afraid to take on the best.

"My friends convinced me to have a go so I thought 'Why not?'" she said.

Whiley started off scratch and led from start to finish.

"I started to feel it in the last lap," she said. 

"It was nice to be able to hold them off."

Cowley, the backmarker on +11 mins and 15 secs, clocked the fastest time of the day, an astonishing 20.8.

"​I didn't expect to be as fast as that," he said.

"It's a good course. Even in wet, wintry conditions you can still walk fast."

Albin Hess won the Masters 3km walk and Mackayla Davison the Uunder-18 3km walk. 

Scott Peart won the under-12 boys 1km event and Maddison Vaughan the under-12 girls.