Mike Pence won the VP debate by a landslide. Unfortunately for Donald Trump, VP debate are pretty much meaningless. Mike Pence not only won on policy, but he was much better at at debating and having a conversation than Kaine. This likely is due to the fact that he was a talk radio host before a politician. Pence won the debate because his composure was better, he rationalized his running mate's actions better than Kaine, and his points were clear.
Pence kept his composure very well during the debate. Kaine was on the attack for much of the debate and Pence just shrugged him off and didn't let him get to his head. Unlike his running mate, he is capable of still getting to his point without having to protect his ego. He was being interrupted at almost every question and still got to his points. Tim Kaine's interruptions came off as rude and inconsiderate, rather than commanding. While Mike Pence had his fair share of interruptions he used them to finish what he was saying rather than disrupt.
Mike Pence had a tough job, he had to defend Donald Trump's statements and policies. Pence did an excellent job of this. Whenever Kaine brought up an offensive of stupid comment Trump made, Pence looked into the camera and shook his head in a way that made seem as if Kaine was out his mind. Undecided voters know that there is a lot of lying in a political debate, and the way Pence shook his head helped persuade voters that Kaine was lying and he is right. This has a real impact to how voters perceive the candidates administration.
Pence's points were cohesive and direct. Whether or not his policy would work is up for discussion, but clearly he presented his argument far better than Kaine. Kaine's answered were scattered all over the place, he had inconsistent answered that were correctly rebutted by Pence. Kaine's interruptions didn't help him seem correct. He came off as defensive and scared, rather than confident and correct.
To finish Pence clearly won the debate because of his debating skills, his conscience points, and ability to defend his candidates statements.