So, so close; but I'm pretty sure at least some of this would be retconned later:

From 1971, Hulk #141, reprinted in Marvel Super-Heroes #92, "His Name is...Samson!" Written by Roy Thomas, art by Herb Trimpe and John Severin.

Recently returned from Jarella's micro-world, the Hulk is mostly just wandering about confused; as Major Talbot and General Ross seek help for Ross's daughter Betty, who had been transformed into a crystal statue after a blood transfusion with the Sandman in Hulk #138. Should they seek the help of a biochemist like Henry Pym or Hank McCoy, or go all-out and get Reed Richards? No, let's go with a psychiatrist, Leonard Samson...really? Well, he does have a big plan, to cure Betty and Bruce Banner!

Samson's machinery drains the Hulk's "libidinal energy--his psychic force" and shoots it at Betty, curing her and Banner immediately! Still, curing Betty didn't take that much juice, so a notion occurs to Samson, to use the leftover power on himself, transforming him into a super-strong, green-haired he-man! Now feeling like the full package, Samson asks Betty out, before she can be reunited with Bruce, who feels like a 98-pound weakling again. It doesn't take long for the jealous Bruce to do the only thing he thinks he can, namely step up and tell Betty how he really feels about her re-dose himself with gamma rays and become the Hulk again! (Pfft, talk about your feelings? Lame!)

Samson actually had wanted to face the Hulk, who feels like he had "been away--locked in some deep, dark place." Samson thinks between his strength and intellect, he should be able to mop the floor with the Hulk, but forgets the Hulk gets stronger as he gets madder, and the Hulk floors him. Betty runs to his aid, though; and the Hulk only knows that he feels like he may have won the fight, but lost something else...

Again, I think it's been retconned later that even if the gamma energy is drained from the Hulk, it just builds back up in him again. Maybe? Still, Doc Samson is a good foil for the Hulk, and would be punched in the face many, many times over the years to come.