Thor for sure... she would do very well mind you.. and make a very good fight of it. Problem is, much like with Supes, eventually Thor's strength and striking power would be the difference.
The only advantage Wonder Woman has is -movement- speed. Which just isn't enough. Thor's stronger, tougher, more durable, more experienced -if that matters- and at the very least just as formidable as she is in hand to hand.
Reflex/HtH speed too, an area in which she surpasses the likes of Superman and is one of her strengths.
Also skill-wise, Thor's formidable but HtH is not his specialty, weapons combat is. Herc is better than him by his own admission, and Diana should have an advantage too.
Lulz. Diana should have no advantage over Thor in hand to hand and neither should Hercules. That was a writer throwing Hercules a bone because he felt Thor's advantages over Hercules were unfair.
I love it when people bring up a single instance out of their over half a dozen fights. I'm going to start mentioning the scene where Thor comes of as physically above Hercules more often.
That was by the way their second fight. Continuity speaking, Hercules has never shown said advantage again and Thor even broke out of a similar hold in the future.
Thor is accustomed to fighting hand to hand. His done this, plenty of times.
Wonder Woman is basically all mele any way. Thor uses all kinds of powers and hammer.She is used to fighting beings as versatile as he is with her limited powers while he can't even beat the hulk with all of his powers. So if you dumb him down, she's gonna win. She is faster than he. Speed is a problem for Thor. Look at how Gladiator did him. Mix in Batman like skill, Superman like strength, and someone just as strong and tuff as he is and Thor is not winning this fight.