Seven-time world champion
Pacquiao, who became the first boxer to win seven championships in as many weight classes, underwent urine tests twice -- before and after the fight -- and both came back negative, said
Immediately following Pacquiao's win over Cotto, fans inside the MGM Grand Arena pleaded for a megafight with
Mayweather Sr., Floyd's father and trainer, told SI's
Floyd Sr. offered no evidence to support his claim.
Since 2002, Nevada has required fighters to submit urine samples before every fight. Those samples test for 40 types of steroids, diuretics and masking agents. In his 10 Las Vegas fights, Pacquiao has never tested positive, and his conditioning coach,
Pacquiao has been bombarded with accusations of doping, having conquered seven weight divisions since entering the sport at 106 pounds when he was 16. And after Mayweather Sr.'s comments following the Nov. 14 bout, there has been speculation that if a megafight between Floyd Jr. and Pacquiao is agreed upon, Mayweather's camp may place stipulations in the fight contract that would require both fighters to take separate, mandatory drug tests in addition to the required tests by state athletic commissions.
But at 10-0 with his Nevada drug tests, Pacquiao has provided plenty of proof he cleanly fought his way to seven world titles.