Daisy Ridley explains how Rey beats Kylo Ren
https://www.youtube.com/watch?v=FVuutYbpRcY
Funny considering how Ren took down Luke's whole jedi order and was the leader of the Knights of Ren. Mary Sue to the rescue!!
Well, Kylo and the knights took down the Jedi students.
Also, Kylo didn't even want to beat her, he wanted to train her, and he easily had the upper hand for most of the fight.
What did she do to win? She focused on the Force, just like Luke shooting photon torpedos with the Force even though he had no training (and what a time to turn off a targeting computer; When the entire Rebellion is at stake).