Just a little extra information regarding the Kylo/Rey lightsaber fight in TFA.

Kylo Ren’s biography on starwars.com:

“Kylo faced his father inside the First Order’s Starkiller Base, and struck Han down with his lightsaber. But this shocking act of patricide didn’t make the former Ben Solo feel stronger – somehow he felt weaker. Rey then bested Kylo in a lightsaber duel, sparing his life. Kylo Ren had hoped to end the conflicts that caused him so such pain, but found he remained at war with himself, more lost than ever.”

http://www.starwars.com/databank/kylo-ren

Rey bested Kylo, sparing his life.

Force Awakens screenplay:

CHEST. HE GOES DOWN, SUDDENLY A FEARFUL MAN, A LARGE BURN
SCAR SLASHED ACROSS HIS FACE! He still reaches for his saber.
And she could kill him – right now, with ONE VICIOUS STRIKE!
But she stops. Realizing she stands on a greater edge than
even the cliff – the edge of the dark side. The earth
SHAKES. The earth splits. A gully forms.

http://www.imsdb.com/scripts/Star-Wars-The-Force-Awakens.html

There is no doubt. Rey defeated Kylo in TFA, and she spared his life. That’s what Abrams and Kasdan intended, and that’s what’s in the film.