Gout Gout has obliterated his own national 200m record with a stunning sub-20 run that would easily have outpaced Usain Bolt at the same age.

The 18-year-old ran 19.67 at the national athletics championships at Sydney Olympic Park on Sunday to become the first Australian to legally break the 20-second mark over 200m.

Gout blitzed Jamaican legend Bolt's under-20 time of 19.93 set in 2004 to claim the world record in the age group.

Only American sprinter Erriyon Knighton has gone faster at the same age, but his 19.49 run in 2022 was not ratified because he failed to meet anti-doping testing requirements.

The Queenslander also smashed his own national record of 20.02 in his title defence, a mark also bettered by runner-up Aidan Murphy (19.88) on Sunday.

It is just the latest record set by the much-hyped teenager, who broke Peter Norman's 56-year-old Australian 200m mark when he clocked 20.04 seconds in 2024.

Gout had run 19.84 with an illegal tailwind in Perth last year to be crowned national 200m champion for the first time.

"I've been chasing it ever since I got that illegal sub-20," Gout said on Sunday.

"It's been on my mind this whole year and these past couple of months.

"For the past week, in my head, I would tell myself I'm running 19.75, and obviously 19.67, so, you know, gotta love it."

Gout said his sizzling run in Sydney was a statement to the athletics world.

The 18-year-old pulled out of the Commonwealth Games to focus on the 200m at the world under-20 championships in Oregon, which start on August 5, three days after the Games end.

Gout will be out to raise the stakes again in Oregon, given sprint king Bolt had kicked off his record-breaking career with 200m gold at the 2002 world juniors.

"It's a big weight off my shoulder knowing that I ran it legally, and I have the speed and body to run times like that," Gout said.

"I'm still only 18, just turned 18, so I definitely think I can go faster for sure."

Gout's great rival Lachlan Kennedy wasn't in the 200m field, withdrawing from the event after running 9.96 for the second time in as many days to win his first national 100m title on Saturday night.

"I was very itchy (watching Kennedy) for sure. Obviously props to Lachie," Gout said.

"He told me it's all me, so I did my thing for sure."

In other results on Sunday, middle-distance star Jessica Hull (15:13.21) claimed victory in the 5000m after withdrawing from the 800m due to soreness.

Hull had lost her 1500m title to Claudia Hollingsworth after tripping while trying to defend a challenge from the 20-year-old rising star.

Hollingsworth was pipped on the final straight in the 800m final on her 21st birthday, outpaced by back-to-back winner Abbey Caldwell (1:58.57).

Defending high jump world champion Nicola Olyslagers cleared 1.99m on her third attempt to claim victory, with Eleanor Patterson (1.93m) settling for second.

But pole vaulter Kurtis Marschall endured a nightmare outing and failed to make a height.

Two-time world champion bronze medallist Marschall fell short of 5.46m at three attempts, with Jack Downey (5.24m) taking victory.

Peter Bol held off a challenge from youngster Luke Boyes to win his fifth straight national 800m title in 1:45.60, prevailing by 0.13 seconds.