Depends on the skill level, defense, stamina, etc...There's other factors involved.
Great chins beating great punchers:
Tex Cobb-Earnie Shavers
Muhammad Ali-George Foreman (Foreman's chin was very good too)
Ray Mercer-Tommy Morrison
Bernard Hopkins-Felix Trinidad
Salvador Sanchez-Danny Lopez
Julio Cesar Chavez-Edwin Rosario
Great punchers beating great chins:
Thomas Hearns-Roberto Duran
Bob Foster-Dick Tiger
Ray Robinson-Gene Fullmer 2
Naseem Hamed-Wayne McCullough
Diego Corrales-Jose Luis Castillo 1