A variety of injuries, including a fractured left leg, appeared to signal the end of Maurice Greene as a force in world sprinting.

The Olympic 100 metres champion and former world record holder broke his leg when he was thrown from his motorcycle on a Los Angeles freeway two years ago.

Greene kept the accident quiet and refused to make excuses for his subsequent fluctuations in form.

Tim Montgomery claimed his world record in 2002. Kim Collins then supplanted the American as world champion in Paris last year after Greene hobbled out injured in the semi-finals.

There had never been any mistaking the Greene pedigree. With four individual world titles, including a 100-200 double in 1999 and the Sydney Olympic gold plus the previous world record of 9.79 seconds, he is one of the great sprinters.

But in view of the brief life span of the fast men, his time at the top seemed to be over after his last injury in Paris.

Greene had other ideas. Determined to retain his Olympic title in Athens aged 30, he beat Montgomery comprehensively in April. He then clocked 9.78 seconds, equal to Montgomery's world record, albeit with an excessive following wind.

Confirming he was back to his best, Greene raced to victory in the U.S. trials, clocking 9.91 seconds ahead of Justin Gatlin and Shawn Crawford.

The born-again Californian, who moved from Kansas City to train with John Smith in Los Angeles, was back.

"When I'm healthy, people see what I can do," he said. "The world record is very possible this year. I just have to execute it."

Athens has a particular resonance for Greene. He won his first world title there in 1997.

It was also the venue for his world record of 9.79 seconds. "Athens is my second home," he said.

Greene also has no doubt about his place in history, conceding only that Carl Lewis might have the edge after winning consecutive Olympic titles. A third American, Archie Hahn, is the only other person to retain the 100 title.

"I have surpassed all of the people before me," he said. "I have done more than they have. I have run faster than they have.

"The only one is Carl. He won two Olympic gold medals."