Ponga has six appeal for Junior Kangaroos

Moved from five-eighth to fullback in March for Newcastle after his three-week halves experiment failed, Ponga starred playing in the line for the under-23s.

He put Brian Kelly and David Fifita in for tries in the first 17 minutes, as the star-studded Australian side went at close to a point a minute for the opening hour at WIN Stadium.

He also started the second half on fire, throwing a cut-out ball for Campbell Graham before he skipped downfield with his trademark goose step minutes later.

New Knights coach Adam O'Brien has already confirmed Ponga will play next year at fullback and not five-eighth.

And the Queenslander is happy to oblige, insisting Friday afternoon's flogging can't be considered as any kind of trial run for the NRL.

"I didn't make many tackles so I was having a ball out there. When I play No.6 in the NRL, everyone tries to get at me," Ponga told AAP.

"It's pretty easy to have the ball when you're attacking all the time.

"That wasn't the NRL - you can't compare that.

"We respected them and they showed up in the second half. It was hard at times. If you look at the team we had, we had beasts all around the park."

Regardless, it again shows why questions will no doubt linger for the majority of his time in the NRL about whether he should return to the frontline.

The 21-year-old said he didn't know whether he would want to play halves in the second half of his career.

"I don't know. In five or six years, I will know a lot more about the game," Ponga said.

"I'm still learning what it takes to be a professional in the game.

"I will play wherever is best for the team."

South Sydney winger Graham finished with a hat-trick in the 12-tries-to-one romp, with his last set up by an AJ Brimson break.

Victor Radley, Zac Lomax and Ryan Papenhuyzen all had doubles, with the latter dominant at fullback in a team littered with some of the NRL's biggest names.

Australian Associated Press