Jamaican sprinter Asafa Powell has already achieved plenty during his glittering career, but the former world record holder insists his best is yet to come.

Jamaican sprinter Asafa Powell has already achieved plenty during his glittering career, but the former world record holder insists his best is yet to come.

Powell has broken the 10-second barrier over 100m some 88 times since bursting on to the scene last decade and even held the world record for just short of three years between 2005 and 2008.

But the 30-year-old has failed to produce his best on the big stage, with a fifth-placed finish his best effort thus far in the blue riband 100m event at the 2004 and 2008 Olympic Games.

But Powell, who is currently in Australia to compete in the 132nd running of the Stawell Gift, believes he can still get better.

"You haven't seen the best of me yet," Powell said on Wednesday.

"Most of my career I have been injured, but I have been working a lot harder.

"I need an injury-free year and then you will see the best of me."

Powell has fond memories from his previous trips down under, having won gold at the 2006 Commonwealth Games in Melbourne at the MCG in a time of 10.03s.

But a trip to Stawell, some 237 kilometres North West of Melbourne, to compete in Australia's richest foot race is something new for the explosive sprinter.

At Stawell, Powell will attempt to become just the third man to win the 120m handicap event from scratch and the first since Josh Ross won on the famous grass in 2005.

And Powell says he is in good shape and ready to leave his mark on the small Victorian country town.

"I have been working very hard and I am in pretty good shape," he said.

"I train on grass between September and February so I am used to the grass.

"It is a big challenge and it is something new, but I am excited about it.

"I am here to compete and I am going to give my best."

Powell has been installed as the $4 favourite to salute in Stawell, with two-time winner Ross unwanted in betting and as much as $23 available.

But Ross, who will start only one metre ahead of Powell, said it would be foolish to write him off.

"I think I am ready to go fast," Ross said.

"I have done it twice before and there is no doubt I can do it again and create history."