Yeah, that is the fight of two of the toughest and strongest actresses and therefore I fight to dream of. They are almost of the same height (Charlize: 5'9 1/2 and Yvonne: 5'9 1/4). I think Yvonne seems to have a bit more weight and a bit more muscle mass, but they are both almost similar. Both blonde beauties are pretty tall, very fit, incredibly flexible and have martial arts skills. These facts already make them to very dangerous and hard fighters.
I remember Yvonne as Sara in "Chuck" and Charlize in Aeon Flux. Both could show there physical skills and we have an imagination of how strong these gorgeous bodies are. Both can crush bones easily.
The fight would be dominated by lots of powerful kicks and some tough punches as well, not so much wrestling. It would be a very brutal and long fight and both are similarly strong. However, I think although there kicks and punches or even their endurance are almost similar, Yvonne has a slight advantage, especially cause she is a bit faster and has a little bit more power. Although I love Charlize I think she would go down by the speed and the hard kicks of her younger opponent. So we can say that Yvonne has dethroned the former queen Charlize. However, Charlize is still a tough girl and actually still has her heyday of strength and is even stronger as she used to be in her twenties. But for the moment Yvonne is a bit too much for her