
She zoomed home from off the pace with a powerful turn of foot run to down the Godolphin entry Special Snap (Shooting to Win), who looked certain to win the 1200 metre juvenile fillies maiden.
Havin' Fun scored by half a head and was one of four winners on the day for Blake Shinn.
"I'd like to thank Stuart Ramsey for supporting me with a good filly like this," John Sargent said.
"He puts a lot of money into the game, so it's great to get a good result for him.
"She'll probably have another run or two and then have a little break."
Havin' Fun is a half-sister to stakes-winners Panipique and Glenall as well as stakes-placed Tribal Rock being the sixth winner from seven to race from stakes-winning Spinning World (USA) mare Our Quivira.
Rising 19, Our Quivira has not had a foal since Havin' Fun, but was covered last spring by Zoustar.
Havin' Fun is the tenth Australian two year-old winner this season for Vinery Stud's All Too Hard, who stands at a fee of $27,500.