Australian cricketing great Steve Waugh had trouble finding enough superlatives to describe Usain Bolt's sprinting feats.
Australian track champion Cathy Freeman was literally lost for words and, unable to speak after losing her voice, had to scribble her reaction down on a piece of paper.
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"Bolt, like Michael Johnson, took sprinting to another level, in fact human experience in general," she wrote.
A meeting in Beijing of past sporting heroes from Edwin Moses to Daley Thompson was the perfect chance to gauge what yesterday's champions thought of today's double world record holder in the 100m and 200m.
At a gathering in the Chinese capital of sporting ambassadors for the Laureus World Sports Academy, they were in awe over Bolt when questioned.
Former Australian cricket captain Waugh said: "I was lucky enough to be in the stadium when he won the 100. That was one of the best sporting moments I have seen.
"He looks like a once-in-a-lifetime champion. He has got charisma which the sport really needs. It's scary how good he might become."
Hurdler and dual Olympic gold medalist Moses said: "He is an athlete who comes once in every five or six generations. There are very few people who can have that kind of impact."
British decathlete Thompson, another dual Olympic gold medalist, treasured the experience.
"Any time you see a man run faster than any other human being who has gone before is a very special moment and he is obviously a very special athlete.
"He seems to be enjoying his athletics. As well as being the fastest man in the world, he seems to have a bit of perspective on it. It should be fun and he should show that.
"You want to show people that as well as being a great athlete that you are a human being as well.
Michael Johnson, who dubbed Bolt "Superman 2" on Wednesday after he took away his 200m world record that had stood since 1996, was in no doubt.
"It was an incredible race to watch and be in the stands. It was the most amazing athletic performance I have ever seen in my life."
