Round 1: In Character, Thor should take this rather easily. He would hold back at first but when he gauges his opponents power, he lets loose. Not to mention his many strength feats and impact feats.
Round 2: MMH can phase through Thors body and possibly take out what he wants. Thor can shock MMH before he even does it. MMH can definitely blitz Thor, but how much of that would put down a bloodlusted Thor who annihilated a solar system while fighting Silver Surfer, but I don't know what story that was from.
This fight actually can go either ways. Especially since Thor is a master with magic and Martian Manhunter is a powerful telepath, but Thor has fought and resisted very powerful telepaths in the past, one notable being Moondragon and the Phoenix-force Emma Frost who had 1/4 of the Phoenix-forces power(Namor was eliminated at this time I believe), which I would guess makes her 1/4 of a Skyfather or higher than that. I know the Phoenix is extremely powerful, a casual galaxy buster, but I'm not certain of how that can translate with Emma Frost and Thors TP resistance since MMH has telepathically taken down at least Herald level beings before.
I can't say who wins Round 2. I don't know enougha bout MMH to give an unbiased answer. I've seen very little of his strength feats and his impact feats are shy in comparison to Thors.
Because of my bias towards Thor and my ignorance of MMH, I will give it to MMH because there may be something I am missing about a bloodlusted MMH.
Round 3: Peak forms? As in their strongest? Well that would be Fernus vs Rune King Thor, oh....oh poor Fernus.
If he doesn't count then I'll go with God King Thor, oh...oh poor Fernus.
If that doesn't count then I'll go with Dark Sword Thor?...fuck! that's galaxy busting level.
What is with the love for Thor in marvel now? I remember in the 90's he was no where near this popular. And now he's a girl!