Olympic 100-metre champion Usain Bolt will lose his crown to compatriot Yohan Blake unless he quickly fixes technical problems with his race, former world record holder Maurice Greene told Reuters yesterday.

The American said Bolt's vulnerability in the first 60 metres, already exposed this year by the younger Jamaican, gave his rivals the scent of gold that was absent in Beijing four years ago.

"If Usain was running like he was in Beijing, he would win hands down," said the 2000 Olympic gold medallist. "But he is not running like that."

Body position out of the starting blocks and in the first 60 metres are hurting the world's most famous sprinter, Greene said.

"Those problems...bring everybody closer to him, which makes him susceptible to losing," said Greene, who is serving as a television analyst at the Games.

"Usain is the more talented, but Blake has a better technical race," added Greene, who correctly predicted Blake would win last year's 100m world championship in which Bolt false-started.

Blake, the year's fastest at both 100 and 200, also prevailed in last month's Jamaican Olympic trials in which Bolt was slowed by hamstring problems.

Although there has been much speculation about Bolt's fitness, Greene said he did not believe he is currently injured.

"All of his problems are technical," Greene said.

Bolt looked sluggish in both Jamaican races, prompting many to predict the lanky sprinter would fail in his bid for a repeat in the 100.

He badly wants both golds to secure his place as a great in the sport he dominates. No man has ever claimed repeat Olympic titles in both.

Bolt will win the 200 hands down, Greene said, but there will be no runaway victory by anyone in the 100.

"Not unless the freak comes out in Usain Bolt," said Greene when asked if anyone could duplicate the Jamaican's two-tenths of a second victory in Beijing.

"He is only one that can do that. He might be capable of doing it again. I just don't see from the races I have seen that he is in that type of shape."

Beyond Bolt and Blake, the race for the bronze is wide open, Greene said.

Americans Justin Gatlin and Tyson Gay, Jamaican former world record holder Asafa Powell and Trinidad and Tobago's Keston Bledman all should be in the mix for the final medal.

Gay, the world's second fastest man, has the speed to run with the best when healthy, but Greene said he was concerned about his hesitancy to go all out at the start because of hip surgery that kept him off the track for nearly a year.

Gatlin's tendency to rush his transition could cost the 2004 Olympic champion who served a four-year doping ban between 2006-10, Greene said.

Powell has the talent, but his poor record in major championships makes him suspect.

"If he is relaxed, he might beat everybody," Greene said.