Four-time world heavyweight champion Evander Holyfield believes Britain's Danny Williams has a "great" chance of beating Vitali Klitschko.
"If he fights the way he fought Tyson he's got a very good chance of winning," Holyfield told BBC Sport.
"Klitschko doesn't appear to be a good inside fighter and if Williams works him inside and puts a lot of pressure on him his chances are looking great."
Williams fights Klitschko for the WBC crown in Las Vegas on 11 December.
Holyfield added: "Even though Tyson's a different kind of fighter, Williams definitely showed he can endure some pretty hard shots against him.
"And although he's fighting a guy who's not 5ft 10in but 6ft 7in, I still think it will be a good match-up."
The 42-year-old Holyfield returns to the ring against Larry Donald in New York on Saturday on the undercard of the Byrd-McCline, Ruiz-Golota world title double-bill.
And he confirmed his goal is still to win the undisputed crown he last held in 1992.
"Hopefully I'll have a title fight next. Don King gave me his word that I would and hopefully he'll stick to that."
However, "The Real Deal" has looked anything but in recent times and has won only two of his last eight bouts.