The Brazilian stormed to a world record time of 46.91 to stun Olympic champion Alain Bernard, who came in second ahead of compatriot Frederick Bousquet.

“I saw Bernard in the last 25. I was hurting a lot but I thought he was hurting too because he wasn’t catching me,” Cielo Filho told reporters after beating the absent Eamon Sullivan’s Beijing Olympic mark of 47.05.

“I think the first 50 metres was the key to the race. I think today was just my lucky day.”

It was a bitter moment for Bernard, who had breached the 47 second mark at the French championships in April but his time was not ratified because his hi-tech swimsuit was not approved.

Polyurethane suits will be banned from next year after controversy over the scores of world records they have prompted, seven being shattered on Thursday to bring the total number for the championships to a staggering 29.

The worlds, which end on Sunday, will stand out in the swimming annals with many wanting asterisks to be put by records set in the suits, knowing they could take years to break when the sport returns to mere textile costumes.