Juan Manuel Marquez says he needs to knock out Manny Pacquiao in Las Vegas on Saturday to be sure of victory.
The long-time rivals have met three times previously, with Pacquiao awarded two disputed decisions after their first bout ended in a draw.
Marquez, 39, was upset Pacquiao was awarded the fight when they last met in November 2011, but the Mexican hopes not to rely on the judges this time. Play media
Pacquiao defends controversial win
“I am looking for the knockout,” Marquez told BBC World Service.
“I have trained really hard and I feel ready.
“I am looking for the knockout because the judges gave another decision [when they last met]. I need to do a perfect fight.”
At 33, Pacquiao is six years younger than Marquez but has not stopped an opponent in his last five fights spanning three years.
The Filipino fighter lost his last fight against American Timothy Bradley in June, a bout most observers thought he should have won.
“I have prepared more,” said Pacquiao. “I am expecting [Marquez] to prove something because he is claiming he won the [last] fight.”
