Not to beat a dead horse here but, Juggernaut can only be KOed by mental attacks, Thanos has mental attacks, Juggernaut has a helmet to protect him from mental attacks, Thanos is strong enough to remove his helmet.
Im honestly lost how this is in such debate. Thanos is one of the few beings around Id give a near flawless win record against Juggernaut (Martian Manhunter and Despero being others, as Id say most any Super Physical Brick with mental powers would be).
IF Thanos simply punches or blasted Juggernaut, he would lose. If Thanos has no mental attacks, he would lose. But Thanos is WAY to smart to simply physically attack Cain, and WAY too tough physically to be taken out by him even close to soon.
Hope I dont get the wrath of WP on me again 🙂, I just feel that there is honestly no way for Cain to get a win record against Thanos UNLESS they are simply punching each other to death, and Thanos refuses to use his mental powers.