Oof. He's too slow to turn and block, and receives a glancing blow on his right flank for his troubles, her sword extending her reach past what he can see of her, and he knocks her blade away too late. First point to Sif, then.

He's not one to dwell on his mistakes in the thick of battle, though, and swiftly counterattacks as he would've back in the training yards of Asgard, finding those cracks in her defense and exploiting them as best he can, his sword scraping along her armored side or sliding down her blade to strike at her wrist. Whether or not she says anything out loud, he can see her cursing herself for her inattention and devoting renewed attention to her form, pressing her advantage where his weakness is more obvious.

It's almost funny, that both of them are so hobbled that their decrease in skill is fairly matched, and Thor can't stop grinning at the irony so that he's not paying enough attention when she gets a solid blow in with the flat of her blade on his blind side, his cheekbone smarting from the impact. Ouch. Now who's not paying enough attention, Thor?