Middleweight Challenge against Hopkins

De La Hoya attempted to unify that title with the three other world middleweight championships, held by Bernard Hopkins, on September 18. He lost to Hopkins by a ninth round knockout, in a fight he was arguably winning. A left hand to the body sent him to the canvas, knocking De La Hoya out for the first time in his career. Hopkins was ahead on two scorecards by the scores of 79-73 and 78-74, while a third judge had De La Hoya winning 77-75.[5] De La Hoya made $30 million for the fight and Hopkins, who made only $300,000 in a fight just nine months before fighting De La Hoya, got a minimum of $10 million. It was the biggest payday of Hopkins's career. Hopkins would later join de la Hoya's own boxing promotion firm; he owns twelve percent of univision Golden Boy Promotions.

Source: http://en.wikipedia.org/wiki/Oscar_de_la_Hoya