Hey, I give credit where credit is due. I've admitted when I think Thor loses plenty of times.
That is not to say Thor can't win here. His best option would be to strike first and go for the soul/spirit manipulation/absorption route which isn't something his likely to due, and Sentry is the only one here whose going all out.
Well, the moment Sentry attacks it's over. He'd just erase Thor the way he did Molecule Man. Like I said, Thor's only hope is to attack first before Sentry does anything and go for beyond physical damage, as doing something like destroying his body is futile. I think that tactic might warrant Thor a win or two, but that's about it.
I think Sentry wins. We've already seen the Void dismantle Thor along with many other heroes in Sentry's first series. There was nothing they could do then. I am sure this will change when it (if) happens in siege.