The Paralympic champion was ready to leave life on the track behind him after a shattering defeat at the Rio Paralympic Games before coming out of retirement to try and reclaim his 100 metre T38 crown.

O'Hanlon has competed in the T38 classification for people with cerebral palsy since leaving school in 2005, representing Australia at the Paralympics three times.

But the experience on his resume did nothing to ease the nerves ahead of the world para-athletics championships - O'Hanlon has never felt such pressure.

O'Hanlon was undefeated in the 100m T38 classification before he lost his title in heartbreaking fashion in Rio.

But the 29-year-old reclaimed the top gong after clocking 11.07s (-1.6), just millimetres ahead of China's Jianwen Hu.

"Coming into these world championships, it's the most pressure I've ever been under," O'Hanlon said.

"Every other time in my career, I knew I could win from the start line, but after coming second in Rio, I had to prove that I am number one.

"To come in, to be able to perform on the big stage again is amazing. This is the best medal I've ever won."

O'Hanlon has now drawn level with Paralympic great Neil Fuller as Australia's leading medallist at the world para-athletics championships with 11.

It's a record O'Hanlon could never have dreamed of, especially given he made the decision to leave the sport last year.

"To be able to follow in the footsteps of a great man like Neil Fuller is awesome," O'Hanlon said.

"I never thought that I would get there in my career, that I'd be one of Australia's top medal takers."