Iīm thinking Frazier. This has been debated on this forum before, and alot of people tend to believe Tyson would knock out Frazier early because of what Foreman did to him. I beg to differ. Foreman just overwhelmed Frazier and threw him around like a rag-doll. Tyson can punch almost at Foreman level, but is not that strong. Also, he lacks the heart needed to trade with Frazier.
Tysons only chance would be to take "Smokin Joe" out early, and I donīt believe he could. He would maybe knock him down a few times and take the first two rounds, but Frazier would get up and keep on coming. Tyson would lose his cool and give up. At this time, Frazier starts "smokin" and from here on out it would be all Frazier. Tyson would be in for a beating.
Frazier by late tko.