After finishing runner-up in her heat to Winona Writer, this time around the five-year-old out toughed her rivals to score the biggest win of her career in the Riverina Championships Mares Final.

Both mares took advantage of short-priced favourite Anntonia being scratched on the morning of the $100,000 race due to an elevated temperature.

It opened the feature up and Goulburn trainer-driver Brad Hewitt was thrilled Yarraman Bella could take advantage despite racing without cover.

"It's what we do it for," Hewitt said.

"We race here regularly anyway but to win one race and run second in another one a group one night is really good."

The mare has only had three starts for Hewitt.

He drove her to a win for former trainer Lloyd Sutton before targeting this series.

Hewitt never expected her to reach such heights.

"I only drove her one night and she won going 52 and she surprised me that night as I didn't think she was that good, but all work since has indicated she's a nice mare," he said.

"I've just done the easy part for the last month and she just keeps on going ahead."

Hewitt is looking to give the mare a break for readjusting his plans.

He then finished second in the group one final for entires and geldings with Send It and also took out a thrilling to the cup consolation with Rockin Marty.