Josh McCulloch stops Thai Nithichai Yoadam in Sydney

And in his latest fight, the 21-year-oid Tamworthian stopped his third opponent, in his fourth pro bout, and thus received a momentum boost ahead of the biggest fight of his career.

At the Sydney Portugese Club in Marrickville on Saturday night, McCulloch - who is undefeated as a pro - dropped experienced Thai southpaw Nithichai Yoadam with a body punch in the fourth of five scheduled rounds at 60kg.

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He then immediately "jumped on" Nithichai "and was all over him" - forcing the referee to stop the contest, McCulloch's trainer, Scott Chaffey, said.

In winning the 20th fight of his career, in his 24th bout, the former national amateur champion has slingshot himself into the defence of his RISE national lightweight title against veteran Thai Orono Pumlumnow in Brisbane on December 10.

That contest will be the No 2 attraction on a promotion headlined by a highly anticipated showdown between George Mann and Jake Lund for the WBC light heavyweight diamond title.

On Saturday night, McCulloch responded in style to a sustained barrage of kicks from Nithichai in the first two rounds.

"I knew coming into the fight that it was gonna be a very, very tough fight," he said.

"He blasted [me] with a lot of big kicks. Cracked me a couple of times on the body.

"But I just had to weather that storm early and put the pressure on in the third round. And I obviously came out in the fourth round and stopped him."

McCulloch has transformed his body in recent years, and is now noticeably more muscular and ripped.

He said his enhanced physique and power was the result of him taking his training to the "next level".

"Everything's just dialled in every single fight camp," he said. "And I guess that's just all showing now."

Chaffey said McCulloch was "definitely" behind after the opening two rounds on Saturday, against a 25-year-old opponent with "180-odd fights" under his belt.

Battling back to halt the Thai had "given Josh a lot of confidence" for "this big challenge" next month, Chaffey said, adding: "The scary thing is, Josh still hasn't hit his prime".

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