Seater, 12, has been training for just a few months in preparation for the National All Styles tournament that was held in Melbourne across the weekend. 

Seater's coach Noni Cox said it was an outstanding achievement by Seater to perform so well and come away with a silver medal.

"It was amazing... we've been training really hard and I'm really proud of him," Cox said.

"It was his first competition and now our eyes are on the State Champs which aren't until September, so we've got a bit of time to keep training and getting better."

Cox has been training Seater in kick-boxing at her home gym Horsham Martial Fitness.

Seater was the only kick-boxer competing at the Melbourne event, which was an all styles competition, allowing participants to use many different forms of martial arts.

Seater made it through the round-robin group stage and into to the final where he faced a more experienced opponent.

"All up there was about 150 people there, he was the only kickboxer but there was karate, kung-fu, taekwondo, all sorts," Cox said.

"Lenny got to the gold medal bout and nearly won it. It was about three points to five in the end so he came close. But his opponent was a bit bigger and a bit more experienced.

"I was so proud of him."

Seater will keep training and aims to compete in several other events in the build-up to the State Championships in September.