Cesar Cielo launches his defence of the Olympic 50m freestyle swimming title on Thursday seeking to extend his dominance in the one-lap "splash and dash".
Cielo, 25, gave Brazil its first Olympic swimming gold with his 50m free triumph in Beijing four years ago.
He set the world record of 20.91sec at the 2009 World Championships in Rome, at the height of the high-tech bodysuit era, and defended that title at Shanghai last year despite the turmoil of a doping controversy that saw him warned over a banned diuretic.
His season-leading time of 21.38, set in Brazil in April, is two-tenths of a second faster than his nearest rival -- American Cullen Jones.
Jones, winner at the US trials in June, is closely followed by the enigmatic Anthony Ervin, who won Olympic gold at the age of 19 in 2000 then walked away from the sport at the height of his powers.
Now Ervin is back and trying to cap his unlikely comeback with another gold 12 years on.
Cielo, however, says the season-leading stats and even world records will be meaningless when the exciting all-out event gets underway with heats on Thursday, with the final to come on Friday.
"Being favorite counts for nothing," the 25-year-old Brazilian said. "I am focusing on doing the best time of my life, whether or not it's the best in history or the best in the competition."
Cielo's Beijing gold cemented Brazil's place among world swimming's elite, and he said they are building on that breakthrough.
Compatriot Thiago Pereira earned silver in the 400m medley on Saturday, and Cielo himself was battling for a medal in the 100m free final before tackling the 50m.
"Nowadays, the world knows that when a Brazilian is in a final, he's there to win, not just to take part," Cielo said. "Brazil is respected as a team."
He said swimming's rise in the South American country was just part of a general boost sports there have received as Brazil prepares to host the 2014 World Cup and the 2016 Summer Olympics.
But with that higher profile comes added scrutiny, and a drugs row overshadowed his 2011 world championships campaign.
Cielo was let off with a warning after testing positive for a banned diuretic on the eve of the championships in Shanghai.
FINA had appealed to the Court of Arbitration for Sport (CAS) after Cielo and three team-mates tested positive for furosemide, but the court ruled the results could probably be blamed on the accidental contamination of a caffeine supplement.
Cielo has shied away from discussing the controversy, saying he wanted to put it behind him.
"I am here to swim fast, nothing more to talk about," he said. "My main goal is to represent my country in the best way possible and to get a gold medal in the 50."
Brazil's Cesar Cielo dives during the men's 100m freestyle heats at the London 2012 Olympic Games, on July 31. Cielo launches his defence of the 50m freestyle title on Thursday seeking to extend his dominance in the one-lap "splash and dash."
Brazil's Cesar Cielo, seen before competing in the men's 100m freestyle semi-finals at the London 2012 Olympic Games, on July 31. Cielo launches his defence of the 50m freestyle title on Thursday seeking to extend his dominance in the one-lap "splash and dash."
Anthony Ervin of the US, who won Olympic gold at the age of 19 in 2000, walked away from the sport at the height of his powers. Now Ervin is back and trying to cap his unlikely comeback with another gold 12 years on.