But that ended in Las Vegas on Saturday when Chavez ran into the fearless American, Frankie Randall, who had toiled in boxing's steerage class for 11 years before getting a chance to move up and fight for a world title.
As a 15-1 underdog, Randall, 32, was supposed to be just another notch on the Mexican's belt, one of about six victims Chavez thought he could count on this year alone.
But Randall, with help from the referee, Richard Steele, who deducted two highly questionable points from Chavez for low blows, stood toe-to-toe with the equally hard-punching Mexican to take away Chavez's World Boxing Council super-lightweight title on a split decision. In the process, Randall knocked Chavez flat on his back with a right to the head in the 11th round.
Steele, at the centre of controversial decisions in major fights at least twice before, deducted a point in the seventh round and again in the 11th for low blows, without the usual warnings.
Judge Chuck Giampa, of the United States, scored the fight 116-111 for Randall. Judge Abraham Chavarria, of Mexico, had the bout 114-113 for Chavez, and Judge Angel Luis Guzman, of Puerto Rico, had it 114-113 in favour of Randall.
'Richard Steele did me a great deal of damage,' Chavez said. Randall said: 'I ran to the mountain top. I went through hell to get here and I made it.'
On the undercard at the MGM Grand Hotel, Simon Brown retained his WBC super-welterweight championship with a majority decison over a very game Troy Waters, of Australia.
Felix Trinidad, of Puerto Rico, kept his International Boxing Federation welterweight title with a unanimous decision over Hector 'Macho' Camacho. Camacho, booed throughout the fight by most of the some 12,000 fans, had a point deducted for holding.
Razor Ruddock was also on the undercard, fighting for the first time in 15 months, since Lennox Lewis knocked him out. Ruddock, facing Anthony Wade, repeatedly lunged at his chubby counterpart. The fight went the 10-round distance, and Ruddock was given a unanimous decision.