This recent CNN article about the 2016 Presidential Debate says "Clinton poked, prodded and quoted Trump's own words, goading the famously thin-skinned Republican nominee. Trump took the bait, repeatedly interrupting angrily or dismissively throughout the night. He couldn't resist attacks, even when it was obvious they would backfire."
I don't know how well this article did at being unbiased, but I agree with what it is saying for the most part. I think Hillary won this debate over Trump.
Like the article says, most of Trump's remarks were attacks towards Hillary, or arguing with her. He looked much more visibly upset than Hillary did. This is magnified on TV, and can really hurt a candidate, and I think it did just that for Trump. Everyone saw him as irrational and acting on emotion, unlike Hillary, who stayed calm and collected and took Trump's attacks in stride.
I think Trump's biggest strategy going into the debate was to attack and criticize Hillary, which backfired a lot, and just made Trump look childish, and not in control of his temper.