Sprint sensation Lachlan Kennedy has joined one of Australian sport's most exclusive clubs as just the second Aussie to legally better the 10-second barrier for the 100m.

Competing at the Kip Keino Classic in Nairobi on Saturday night (Sunday AEST), Kennedy claimed the win against a strong field, stopping the clock at 9.98 seconds into a slight 0.7m headwind.

Teen sensation Gout Gout and Rohan Browning have also recently threatened to go sub-10 on multiple occasions, but it's the 21-year-old Kennedy who has reached the magic milestone first.

The only other Australian to achieve the celebrated feat was national record holder Patrick Johnson, who ran a sizzling 9.93 in Mito, Japan in 2003.

"I was there to win today and bring it home, and I am super-stoked to get the win and the time," Kennedy said.

"It's so good. I can finally say I have run nine!

"I haven't wanted to rush it or put the pressure on myself, I take every race as it comes and I knew it would come eventually."

Kennedy relegated Paris Olympics relay silver medallist Bayanda Walaza from South Africa (10.03) and hometown hero Ferdinand Omanyala (10.07) to the minor placings.

"The crowd was nuts out there. I think there was early movement from someone in the first part of the race, but it actually did me good. It settled the nerves so I was pretty confident out there today," Kennedy said.

"I didn't think a nine was realistic until a couple of years ago. When I was still playing rugby but starting to train and realising I had some speed, I made it the goal."

Kennedy first shot to international prominence when he pocketed silver in the 60m at the World Indoors in China in March.

The main target for him and his friendly rival and fellow Queenslander Gout this year is the world championships in Tokyo in September.

"I'm getting better with every race," said Kennedy.

"It's an advantage to have a long season at home.

"I'm not getting tired, so I'm looking forward to seeing what I can achieve later in the year as we get closer to the world championships."

Kennedy's previous personal best was 10.00 set in the heats at the Australian titles in Perth in April.

At the same meet, Browning won the senior final by equalling his PB of 10.01 and Gout twice clocked wind-assisted times of 9.99 in the under-20 100m.

Kennedy and Gout are both scheduled to race the 200m in the prestigious Ostrava Golden Spike Meet in the Czech Republic on June 24.