Wladimir Klitschko mocked 40-year-old Tony Thompson ahead of their world heavyweight title bout in Switzerland.
Klitschko will stretch his eight-year unbeaten run to 16 fights if, as expected, he beats Thompson to retain his WBO, WBA and IBF titles at the Stade de Suisse in Bern.
The two met in Hamburg four years ago when Klitschko knocked his American opponent out in the 11th round.
Thompson later claimed a knee problem prevented him from being at his best, but Klitschko claims the American made the injury up as an excuse for his defeat.
The Ukrainian brought the issue up at the pre-fight press conference ahead of Saturday's bout as a means of poking fun at his opponent.
"We sat here four years ago and you said you were going to beat me, you told me that you were going to knock me out,'' Klitschko said.
"You were very confident going in to the fight but you lost and after you said you were injured.
"I don't understand why you only said you had the injury after the fight...''
Although Thompson has won his five fights since the Klitschko bout, he is still a huge outsider to beat 'Dr Steelhammer'.
Klitschko has been accused of opting for easier fights in the past but he had no other option than to take on Thompson because he is the IBF mandatory challenger.
"I had no choice (but to fight Thompson),'' Klitschko added.
"I have to defend my titles, but to fight Tony Thompson is definitely not an
easy job. It's not going to be a vacation fight for me.''
Thompson has lost twice in a 38-fight career that stretches back 12 years.
He may be coming towards the end of his career, but the Washington DC southpaw insists he is capable of pulling off an upset.
"My job is to try to crash the party,'' Thompson said.
"I feel wonderful. I'm not beat up or anything.''
Klitschko's last fight saw him knock out Jean-Marc Mormeck in the fourth round while Thompson earned his shot at the 6ft 6in Ukrainian by beating 36-year-old Maurice Harris.
Huge controversy marred Klitschko's previous appearance in the ring. The Ukrainian was at the side of his brother Vitali in Munich when his opponent Dereck Chisora spat water in his face prior to their fight.
Chisora's antics - he slapped Vitali at the weigh-in - caused outrage, but Thompson insists everything will be clean in tomorrow's meeting with the younger Klitschko sibling.
Thompson said: "We came here to do a job. We are not going to spit on each other and we are not going to talk any trash.''