The Greg Horne-trained Naughty Gunn saluted to take home a Mandurah Cup win last Friday night.
A mighty field was assembled following a set of five heats the previous Friday night, and after drawing box three Santa's Magic was always going to start favourite.
But Naughty Gunn turned on her jets in the middle stages and raced to the front with fellow speedster Mottza surging into second.
First Rule after flying out of the boxes was relegated to third and turning for home Naughty Gunn and Mottza looked settled.
Naughty Gunn had more stamina late and was able to claim the group three triumph by half a length in 27.57 seconds.
Mottza was a gallant runner-up ahead of Goblin Monelli who rocketed home from the back of the field to be close up in third position.
Naughty Gunn is owned by Jayson Gunning and from 20 starts now has 10 wins and eight minor placings to her credit.
The Mandurah Cup was first staged in 1979 on the old circuit over 530m.
Hunt's Reject saluted in a time of 31.37 seconds on the grass surface.
Notable winners of Mandurah's richest race include Windfire (1984), Sandi's Me Mum (1991), Reggemite (1999), Flying Emu (2010) and Astrozone (2017).