James Toney at 160 lbs was a puncher. At and 168 -175 lbs + his punching power was deceiving. JT usually broke down opponents with accumulation of punches and two of his best performances were against Barkley and Holyfield. In both fights he broke down them with body punches and right hand leads. James Toney vs Jason Robinson ko in 7 Cruiserweight https://gfycat.com/ReflectingHappygoluckyAmericantoad
Holyfield is one. Wasn't the one punch KO kind, but really got the attention of bigger opponents. Against Tyson, his punches seemed to have as much effect as Tyson's despite Mike being the puncher.
Wilfred Benitez. Never thought of as a hard puncher at all, but he had some power. Just didn't use it much at all because he wasn't a brawler. His KO of Maurice Hope was scary.