Cosmic Thor should stomp hard both rounds honestly, in theory at least, we need more feats from him guys, give him time it's literally been like 3 issues and he has had these amps for like 1 and a half.
I think that Round 2 will be harder. Thor will get more powerful the longer the fight goes on. The only way I see Cosmic Thor beating PG Thor is by incap him in a similar way that Thanos did. Otherwise, I would say that PG Thor will draw it out long enough to surpass Cosmic Thor (Please let the name Cosmic Thor stick with this version of Thor). For now, I say that Cosmic Thor can't do it, based on what we have seen from him.