Australia’s most powerful stable Emma Stewart and Clayton Tonkin will have three key runners in the country's richest juvenile race.

It was confirmed last night Cardigan Dan, Dynamitedan and Loucasso all have guaranteed slots in the $500,000 Ladbrokes Protostar at Albion Park on July 12.

Stewart and Tonkin have the quality and numbers to go one better than when they snared second in last year's inaugural Protostar star with The Highlight Reel, who was beaten a half-head by local star Fate Awaits. Cigano also ran fifth for Stewart and Tonkin.

Leviathan owner Danny Zavitsanos confirmed he and his wife, Jo, their own brilliant youngster Dynamitedan in the slot they share with Warren Viney.

"That gives ‘Team Zav' two runners after Cardigan Dan won the qualifying race at Ballarat a couple of weeks ago, which got him the Durham Park and Ballarat club slot in the Protostar," Zavitsanos said.

"We've got a really good batch of youngsters this year and Jo and I are thrilled to have two runners in such a big race.

"We're unashamed fans and supporters of these big slot races and always want to be part of them when we've got the right horses."

Cardigan Dan won his first start, endured a tough run when fourth in the rich Nutrien final on April 11 and then returned from a freshen up to win the Durham Park Rising Star qualifier at Ballarat on June 12.

He narrowly beat stablemate Loucasso, who will run in the Protostar slot held by the Stewart and Tonkin stable itself.

Loucasso boasts four wins from just six starts, including the $150,000 Australian Pacing Gold final at Melton on May 24.

Dynamitedan comes through a different form line having targeted and won the final of the NSW leg of the Australian Gold series at Menangle on June 14 after a close second on debut in his qualifying heat.

Champion driver Luke McCarthy gave the Zavitsanos and the stable a rave review after the win, which convinced them to target the Protostar with the colt.

Confirmation of the three Stewart and Tonkin runners underlines the extraordinary depth in this year's Protostar.

Premier Queensland trainer Grant Dixon will have his two star youngsters, Fight For Glory and Fire And Passion, in the race.

Unbeaten Victorian juvenile Showmethetanlines, who resumes from a spell at Melton tomorrow (Saturday) night, also has a slot.

As does Brad Hewitt's exciting Rewatch, who ran second in the Bathurst Gold Crown final, but disappointed first-up at Wagga last Friday.

"He's bounced back really well this week and worked super. He's going to Brisbane and I'll run him in the lead-up race (at Albion Park) on Saturday week," Hewitt said.

Unbeaten Kiwi-bred Atua Magic, trained in Victoria by Shane Sanderson, has also snared a slot through Willowood Farms.