Vitali Klitschko, who will step into the ring on Saturday after nearly four years absence, weighed in three kilograms less than WBC heavyweight champion Samuel Peter on Friday, according to AFP.

The 37-year-old former champion from the Ukraine - dubbed "Dr Iron Fist" by virtue of his doctorate in sport science - weighed in here at 112 kgs, while Peter from Nigeria tipped the scales at 115kgs.

Peter, dubbed the "Nigerian Nightmare" with a record of 30 wins, 1 defeat and 23 knockouts, will be defending the title he won against Russia`s Oleg Maskaev on March 8 and starts as favourite.

Klitschko, who boasts the highest overall knockout ratio of any heavyweight champion, is the older brother of IBF, WBO and IBO heavyweight champion Vladimir and last fought in December 2004 against Britain`s Danny Williams.

A knee injury led to his retirement and this is his first fight back as he bids to regain the WBC title so the Klitschko brothers can hold four titles.

His record is 35 wins with 34 knock-outs and two defeats.