WBC lightweight world champion Manny Pacquiao believes he can achieve boxing immortality by beating 10-time world champion Oscar De La Hoya in a bout billed as the “Dream Match”. Pacquiao of the Philippines, who has captured world titles at four different weight divisions, takes on Los Angeles native De La Hoya in Las Vegas on Dec. 6. “This is the biggest fight in my boxing career,” Pacquiao, 29, told reporters on Monday before conducting an open workout. “This is the door (through which) the name of Manny Pacquiao will be known, not only in the Philippines but in boxing history.” The bout is a 12-round, non-title fight contested at the 147-pound welterweight limit. Although the 5 foot 6.5 Pacquiao concedes a four-inch height advantage, the Filipino feels his speed will be decisive. “I feel very comfortable at that weight,” he said. “This is the hardest training I have done in my boxing career and we have focused on speed because that will be the key.” Pacquiao's trainer Freddie Roach, who has produced 22 world champions, forecast the 35-year-old De La Hoya would not last the pace. “You look at the history of boxing when the older guy fights the younger guy, like when (Muhammad) Ali fought (Larry) Holmes or when Joe Louis got beaten by Rocky Marciano,” Roach told Reuters. “It's the younger man's time. I am 100 percent confident. I don't think Oscar will be able to keep up and I think we will knock him out in the late rounds.” Roach knows De La Hoya's style well, having trained him for last year's super welterweight showdown with Floyd Mayweather Jr.. De La Hoya lost on a split decision and he and Roach parted on bitter terms. “I know Oscar's strengths and weaknesses,” Roach said. “He is very consistent and he trains hard for fights but he is just older. The one thing we have to take away from him is his reach advantage.” De La Hoya has a 72-inch reach, five more than Pacquiao. Pacquiao claimed the WBC lightweight championship in June by knocking out American David Diaz, improving his record to 47-3-2 (36 KOs). “Golden Boy” De La Hoya, in the twilight of his career and arguably the biggest name in boxing, has a 39-5 record with 30 knockouts. ‘Any Klitschko will do' British rising heavyweight star David Haye doesn't care which Klitschko brother he fights for a world title - as far as he's concerned the Ukrainians can “flip a coin” to decide which one faces him. Such is the current lack of genuine heavyweight contenders and the fact Vitali Klitschko and brother Vladimir have vowed never to fight one another, that former cruiserweight world champion Haye could get the title shot he craves in a relatively short space of time. The 28-year-old Londoner marked his first heavyweight bout after stepping up a division with a fifth-round stoppage of the experienced Monte Barrett in the British capital last weekend, flooring the American five times. World Boxing Council (WBC) champion Vitali and International Boxing Federation and World Boxing Organization belt-holder Vladimir are both due to make title defenses in the not too distant future. And Haye insists he doesn't mind fighting either of them next although boxing politics, not to mention sporting sense, mean he may not get his chance until next year at the earliest.