Just a week out from the rich Magic Millions Classic, Scarlet Rain has staked a late claim for a start in the $2 million race with her debut victory at Rosehill.

Things didn't go as smoothly for her Gai Waterhouse-trained stablemate Northern Fire who lost rider Adam Hyeronimus in the straight.

Both horse and rider came through unscathed from the incident.

The winner, the $2.70 favourite, was in the lead and out of trouble and held off a spirited challenge from Cudabeen ($12) by a head.

Waterhouse's representative Mark Newnham said the trainer would make the final decision on a Magic Millions start for Scarlet Rain when she returned from an overseas holiday.

"Gai's due back tonight," Newnham said.

"It's a big ask to take her to the Gold Coast but I wouldn't rule it out."

Scarlet Rain's rider Tommy Berry has won the $2 million race twice aboard Karuta Queen in 2011 and Driefontein the following year.

"She was very relaxed before the race and I thought she looked a little bit like Karuta Queen," Berry said.

"I have been waiting for her to race. I don't have a Magic Millions mount other than her but we have to wait and see if she goes up there."

At the inquiry into the fall of the winner's stablemate, Hyeronimus said he was unaware where the pressure came from - he just knew he was going down.

"It's my first race fall in seven years of riding," he said.

Waterhouse already has Slumber Party in the Magic Millions with the filly a $10 chance in a market dominated by Capitalist at $1.70.

Co-trainer Peter Snowden said Capitalist was in fine fettle after a race day gallop on Saturday, prompted by him missing a barrier trial earlier in the week with a slightly elevated temperature.