How is it that Rey was able to over-power the mighty Kylo Ren during interrogation and defeat him in the end? We could blame the fact Ren was injured at the end but still Rey seems a little over-powered against someone who can stop a laser beam mid flight.
One thing i have learnt about people with over powered abilities is that they are always easily seduced by the dark side to keep that power.
Anyway, back on point: Finn
Finn is able to survive so long against Kylo Ren during the lightsaber fight and manages to injure Ren in the process. I guess it could be one of those moments when noobs get lucky or because he's force sensitive, drawn to the light side, can't kill at the beginning of the movie, senses he's got a higher purpose either than running and as a result then mysteriously knows how to wield a lightsaber against a sith lord.
Sigh..I have so many questions.
My favourite line in the movie is Spoiler: "The Scavenger resisted you" Which translates to "Your Such a Noob"