Twenty-year-old hoop Chris Parnham is keen to break his Group 1 status and rates his three-year-old mount in the Kingston Town Classic 2017 field on Saturday Achernar Star a livewire chance at the upset.

Darren Weir’s five-time Group 1 winner Black Heart Bart is the obvious favourite to beat in this weekend’s weight-for-age $1 million Kingston Town Classic (1800m) at Ascot Racecourse.

Drawn the rails, which produced last year’s also Weir-trained champion Stratum Star (2016), the former Perth-trained champ dominates Kingston Town Classic odds at $3 and firming through Ladbrokes.com.au.

Parham meanwhile is aboard one of the three youngsters taking on the older gallopers in the Kingston Town Classic field this year, the Simon Miller-trained Gingerbread Man gelding Achernar Star.

“Black Heart Bart is obviously going to be hard to beat, but three-year-olds have a good record in the race,” Parnham told The West Australian.

The ultra-consistent chestnut has finished worse than second in just one of his eight career starts and is a dual Group 2 runner-up.

Achernar Star faces a task rising in grade, class and taking on an open-age field of rivals on the weekend and currently pays $11 in the Kingston Town Classic odds.

Grant & Alana Williams’ class filly Perfect Jewel is the shortest-priced of the three-year-olds in the mix this year at $6 and firming, while Money Maher is at $26 rounding out the youngsters out to be the fifth since 2007 to win.

Parnham replaces Craig Williams aboard Achernar Star after the globetrotting hoop guided the horse to a brave second behind Perfect Jewel in the Group 2 W.A. Guineas (1600m) last time out on November 25.

Prior to that Parnham was in the saddle for Achernar Star’s 1200m Ascot win on October 28 and the second to Money Maher in the Listed Fairetha Stakes (1400m).

The hoop has had to keep to a very strict diet and exercise program to make the 52kg lightweight to jump back on this Saturday and hopes it will be worth it come Ascot Race 8.

“I’ve just been a bit strict with what I eat and done more exercise this week,” Parnham said.

“I’ve made the mistake of getting there too early and then having to hold that weight, so I’ve just got to time it right.”

Parnham has enjoyed a strong spring – summer season including his third aboard Petrology (on 52kg) in the Group 1 Toorak Handicap (1600m) at Caulfield in mid-October.

That was one of his closest elite level riding efforts in Melbourne following his second on Voodoo Lad in last year’s Group 1 Sir Rupert Clarke Stakes (1400m) behind Bon Aurum.

“I’ve come close quite a few times but haven’t been able to win one [a Group 1 race],” Parnham said.

“It’s been a bit frustrating but I’m only 20, so there should be plenty more opportunities to win one.”

Achernar Star was one of the big winners in this year’s Kingston Town Classic barrier draw with gate four, which last produced a winner in Luckygray in 2012.

“I can pretty much put him where I want from that barrier,” Parnham said.

“He’ll just settle where he’s happy to be.”

To back an upset Kingston Town Classic 2017 result on the weekend at the best summer racing odds visit Ladbrokes.com.au today.