He Was Choked Out By A Snake

What more do we need to say for this particular point? If Hulk is deprived of air, he passes out like anybody else – and on one occasion, a snake was enough to make this happen.

It happened in Incredible Hulk #470 and you can see it happening in the picture above, as well as the aftermath in the picture below.

Granted, this was incredibly bad writing, but you can easily say the same thing when Hulk wins against people he should have no right to win against. It works both ways.