Iron Man, Vol. 1 #62 (1973)

Whiplash Returns
Unable to track down Happy, Pepper and Tony continue their work in Detroit. While working at the Detroit plant, Whiplash (who was hired by S.I. under the guise of Mark Scott) attacks once more with upgraded equipment. Tony is allowed to escape to "find" Iron Man, and returns to face the upgraded Whiplash. Whiplash is able to damage Stark's armour, but Stark disarms him anyway. Realizing that he can't best Iron Man in unarmed combat, he distracts Iron Man by tipping heavy equipment onto him and uses that time to make good his escape.
Release Date: 1973