Kylo's lack of completion of training still rather dominates Rey's complete and utter nothingness of training. She didn't just outright kick his arse physically she got the better of him with Force. That is just stupid.
Maybe we should just show you visuals where things are actually shown:
Kylo commits patricide, becomes emotionally compromised:
(Not shown, Ren getting shot by Chewie.)
Kylo fights Finn, gets cut, hands Finn's ass to him (also probably tiring him out a bit) followed by Kylo fights Rey, gets cut again, shows sincere fatigue:
I mean, really, even the strongest person is going to be pretty exhausted at that point. And she didn't beat him. He was down, but not out. It was a stalemate, because THE FUCKING PLANET SPLIT APART!!
(I do have to admit, I was a little disappointed to learn Luke didn't cause that.)