Clark looked like the better fighter. She obviously won round 1 easily. Herrig barely held onto that body triangle in the 2nd round after the takedown. If she doesn't hold onto that, she loses the round, and the fight.
Also, I remember hearing Clark say something about hurting her arm at some point in this fight. Without the injury, the latter part of the fight probably would've looked much more similar to the beginning of it.
I think Clark takes the rematch pretty easily.