'Australia's Rocky' out to shock Klitschko

Heavyweight champion Wladimir Klitschko has dubbed Alex Leapai "Australia's Rocky" ahead of Saturday's world title bout, when the challenger will try to complete an unlikely rags-to-riches saga.

Leapai sat behind bars in the high-security wing of a north Brisbane jail around the time Klitschko won his first world title in 2006, but now the 34-year-old will challenge for the champion's WBA, IBF, WBO and IBO belts in Oberhausen, Germany.

A bar fight saw the Samoan-born Leapai jailed for six months - "a time that still haunts me today," he said on Wednesday.