The Incredible Hulk Vol.1 #6

Plot

Finding his transformations more and more difficult using his gamma ray machine, the Hulk with Banner's brain also finds that he has Banner's features when he zaps himself to face the alien invading Metal Master and his head does not transform. The power of the Metal Master is too much for the Hulk and he is captured by Ross. Rick forms the Teen Brigade. Hulk breaks free of Ross's bunker and then pulls off one of the boldest victories against one of the most powerful aliens ever seen.