It was pretty cray for her -- looks like she grabbed a rock since she no longer had a weapon. She's never been a gladiator fighter before, but this was pretty much 'bar room fight / seat of your pants" fighting.How many times has a man been in a fight been like, "Yay!, I'm gonna win!! [and then..]"
I think Disco said that the Hound was more likely to win in such a match-up and I'd agree, more times than naught. Brienne just happened to have some decent crit rolls on her d20. I also will note that the Hound was likely suffering sepsis at this point from earlier wounds suffered, so he wasn't in top form.
Epic fight in the short term, a failure in the big scale -- they were fighting over Arya, and both lost in that regard.This fight was epic though. beautiful battle ground. Two Warrior Legends, The Hound, even more legendary, though Brienne will now have songs written about her I'm sure.
It was pretty much two parents trashing each other over the future of their child, and their kid finally flips them both the bird and says, "I can take care of myself, thank you so very much," and walks off.