Brad Parnham has made the tough call to pick in-form mare Amasenus over Indian Pacific and Samizdat for his ride in the Group 3 Roma Cup (1200m) at Belmont Park on Saturday.

The jockey’s new association with Amasenus, a brilliant winner of the Marjorie Charleson Classic (1200m) and Sheila Gwynne Classic (1400m) at her past two starts, won out over his previous successes on Indian Pacific and Samizdat.

Parnham rode the Simon Miller-trained Amasenus in a race for the first time in the Marjorie Charleson and was even more impressed with her dominant last-start victory.

He has ridden Indian Pacific in 17 of his 20 career starts, guiding him to six wins, but was disappointed by the quality sprinter’s first-up eighth to Elite Street in the Northam Stakes (1100m).

“I felt like it was better to go for the horse that’s in form,” Parnham said.

“She’s a very good horse and she always seem to be a bit underrated.

“Her last two wins when I rode her, she has won convincingly.

“Indian Pacific is very capable but he was a bit disappointing the other day. It was a tough call.”

Parnham is confident Amasenus, a winner at 10 of 20 starts, can handle a stern test against WA’s best sprinters in the Roma Cup.

“It’s obviously a step up in grade but I think if you put her in amongst better horses, she might find that bit extra,” Parnham said.

“I’ve ridden her in trackwork on soft tracks and she always works enormous, so she’ll appreciate that if the rain comes.”

Joseph Azzopardi is the likely new rider of Indian Pacific, who is trained by Parnham’s father Neville.

“He looked a bit disappointing on face value, but we’re of the belief he didn’t let go on that hard surface at Northam,” Neville Parnham said.

“Then with Mervyn in the race, he puts the pressure on from the start and takes Indian Pacific out of his comfort zone.

“Back to Belmont and with a bit of rain around, I think you’ll see a marked improvement from him.”

Valour Road, Notorious One, Kaptain Kaos, Free Trade and Nerodio are among the fresh Roma Cup contenders to join the sprinters who raced in the Northam Stakes.

Meanwhile, comeback king Prince Turbo will be set for the Kalgoorlie Cup (2200m) in October after his emotional Eurythmic Stakes (2200m) win at Ascot on Saturday.