8. The Incredible Hulk #122
As much as I'd like to keep this to one-on-one brawls, there actually aren't that many between the Thing and the Hulk. The fact is, if you're picking a fight with Ben Grimm, you're picking a fight with the entire FF, so it's no surprise that a lot of fights on this list have Ben's teammates pitching in to put the jade giant down.
In this issue of The Incredible Hulk, Hulk takes on the entire Fantastic Four, with Ben just barely managing to hold him off by punching him through several buildings.
After holding him off for long enough, though, Reed ends the fight by using a machine he had built specifically for this occasion to knock out the Hulk, giving the FF the win for this round.
Reed planned on curing the Hulk for good now that he had him sedated and harmless, but of course things didn't work out for him on that front. But in terms of fighting The Thing, Hulk is at 0-2.