Chappell dominates field, history books at athletics schools nationals

But after his 13.12-second dash, crossing the line first for his third gold medal just one and a half days into the School Sport Australia 12 years-and-under track and field championships, Lachlan's father Josh said:

"That's what champions do."

The result extended a record-breaking first couple of days at the St Leonards tack for the 10-year-old Sydneysider, after he put his name in the history books not once, but twice on Friday.

The softly spoken St Bernard's Botany student showed his class in the 200m final as he ousted fellow statesman Hafiz Gami's event record by eight hundredths of a second with a time of 26.35, knocking over a marker that was set on the exact same day in 2006.

But he wasn't finished there, showing his versatility and range of ability as he moved over to the field discipline of discus.

Lachlan admitted he surprised himself when he threw 45.18 metres, more than 10m further than second place and nearly two more than the existing record.

Held by Queenslander Mitchell Cooper, the marker was set all the way back in 2005 meaning it just fell short of lasting two decades.

However, Josh believed his son's effort was even more historic than that.

"He got the Australian record on the fifth throw, and then after he ran the 200-metre he came back to throw again and that one was a world record," he said.

Speaking ahead of his 4x100m relay and shot put events, Lachlan said the best part of his weekend so far was the company he was spending it with.

"I like making lots of friends and I have a lot of other [mates from home] here too," he said.

That element sticks with him when competing too, saying that the most important part for him was to have fun while doing it.

With the 2032 Brisbane Olympics on the horizon, Lachlan was reluctant to say he would live up to his new nickname among mates of Usain Bolt.

"I would love to be him, but I don't think I will be," he chuckled.

Josh said his tempered expectations of himself were a sign of how grounded he was.

"He's very humble. He's just won three golds and he'll get in the grandstand, won't mention it, he'll go back to school in Sydney and he won't mention it there," he said.

"That's why everyone loves him and he puts the work in and doesn't complain."

There were other notable moments at St Leonards, with Tasmanian Sid Perrett - who placed second - one of five 11-year-old boys to break the long jump record.

Fellow host-state competitor Lachlan Kleinig (4.27m) grabbed bronze in the 10 boys' long jump.