Manny Pacquiao vowed to score a convincing victory in his upcoming rematch with WBO welterweight champion Timothy Bradley on April 12 at the MGM Grand in Las Vegas.

Pacquiao said on Monday that he is determined to become the first fighter to defeat Timothy Bradley. The former pound-for-pound king admitted that it won't be easy, but he is confident that he is up to the task.

"No one has ever defeated Tim Bradley during his professional career," Pacquiao said via BoxingScene. "I want to be the first name in his loss column. It will not be easy. Nothing at the world championship level is easy."

Bradley previously took a swipe at Pacquiao, saying that the former pound-for-pound king has lost his killer instinct, but Pacquiao insisted that he will prove Bradley wrong in their upcoming rematch.

"I still have the hunger and the desire to win and I appreciate Tim Bradley giving me this rematch to prove it," Pacquiao said. "Unfortunately for him, on April 12, I will not be able to repay him that favor with kindness."

Pacquiao lost his WBO welterweight title during their first showdown in June 2012. The 35-year-old former champion looked like the better fighter in that showdown, but two judges saw it otherwise, awarding Bradley a controversial split-decision victory.

Pacquiao has insisted that he clearly won that fight, and he is itching to prove that he is the better fighter, saying that he is extra motivated in facing Bradley again as he is aiming to reclaim his title.

"Because I am facing Tim Bradley again I am extra motivated for this fight," Pacquiao said. "I may not have won the decision the first time we fought but I know I did not lose that fight. I want the world title he won from me back around my waist. I want to prove I am the better fighter."

Pacquiao is coming off a unanimous decision win over Brandon Rios in November, while Bradley successfully defended his title against Juan Manuel Marquez in October.