A key piece of the Golden Slipper puzzle has been solved in emphatic fashion for the connections of She Will Reign, the filly looming as Australian racing's next rags-to-riches racehorse.

In an industry littered with million-dollar yearlings, She Will Reign cost $20,000 but continued on her unbeaten run in the Silver Slipper Stakes, overcoming an uncustomary slow start before dishing it up to the colts.

In posting the third and most important win of her career to beat Godolphin colt Veranillo ($9.50) by 1-1/2 lengths, She Will Reign earned almost $144,000.

The prize money is almost half of the purse she collected for winning the Inglis Nursery.

Because her Nursery win came against horses with a sales-related origin, her earnings are not counted when deciding a Golden Slipper order of entry.

Her Silver Slipper return is a different story and She Will Reign is now assured a start in next month's $3.5 million Golden Slipper.

But her elevation to clear-cut Golden Slipper favouritism at $3 didn't come without a major scare.

Sent out well into the red, She Will Reign ($1.35) was the last of the seven runners to hit the ground.

The mistake cost her a length and ensured she would race out of her comfort zone after leading to win at Kembla Grange and Randwick.

Yet trainer Gary Portelli is adamant there was never a doubt in his mind about She Will Reign mixing up her racing style

"I already knew but when she missed the start I thought 'this is perfect' because now we can find out for sure if she can race from behind," Portelli said.

"We've learnt something out of today. She's not one-dimensional at all, but it was a big way to learn it."

Jockey Ben Melham remained composed in the face of potential adversity as he allowed She Will Reign to gather her stride.

She settled six lengths off the leaders but Melham saved ground on the turn and She Will Reign joined Veranillo at the 200m before pulling clear.

Showtime, a $26 chance, ran the best race of his career to finish third, a half length away.

"It was probably a blessing in disguise at the start," Melham said.

"It was good to see her do it and do it like that."

She Will Reign will have a lead-up run to the Golden Slipper over 1200m in the Reisling Stakes at Rosehill on March 4.

Trainer John O'Shea is likely to start Veranillo at the same meeting with the colt earmarked for a gear change ahead of the Todman Stakes.

"He probably just needs to execute a bit better in his races and we're hoping he will be better with some head gear (blinkers) on," O'Shea said.