If i'm perfectly honest nobody really won last night.
Kaine started awfully, he was extremely nervous and it showed with his constant interrupting, but he grew in to it the longer it went on. He delivered some good lines and made some extremely valid points. Also, a few times, he got the very last word and Pence didn't even try to respond or reply and in those times there was a little moment of silence and it felt like Kaine's points were just left hanging there, and that should go in his favour.
Pence was on a whole, awful. He is extremely robotic, he comes across as incredibly condescending and patronising and there were too many times where he discussed policy issues that Trump hasn't ever mentioned. He was clearly trying to promote himself a bit on those occasions. There were also too many times were he flat out denied things Trump has said, and the trouble is it was often things that EVERYONE knows he has said. There were also many times where he just didn't bother trying to defend Trump because you could see he had no defence and didn't want to go there.
Neither of them really changed anything at all. Kaine did come across as nervous and irritating while Pence was dull and emotionless and neither came across as Presidential. If Pence thinks he is building a platform to 2020 then in my opinion he has built it on quicksand because it's bad enough that his policies are so archaic and religion based, but he has sold his soul to the devil, and I doubt that will be easy to shake. Every question thrown at him will be about his association with Trump. He can't throw Trump under the bus because he then loses the core Trump supporters and all he will end up gaining are the evangelicals and extreme religious right which isn't enough to win a General Election.
All in all it was a bit of nothing really and I doubt many bothered watching the whole thing, and of those who did, I bet even fewer really give much of a shit about those two.