There are not professional or scientific polling on who won the debate. That takes time but rough estimates had the WSJ proposing that each camp firmly kept their followers and the undecided weren't noticeably moved in either direction. These early polls do not give people the time to pause and think, instant news does not wait. For that I got this from Time magazine online poll.
It is a draw.
My take? I think governance in the 21st century is more complex than ever. The substantive issues are inter-related and not easy to understand. As a result the voting base become divided into two extremes of the smart and the dumb.
Clinton makes no sense to the simple minded and emotionally directed types. These folks do not learn something by reading and thinking. They learn from doing and experience. If in the throes of change they were left behind then the system that is in place is bad and we need someone to completely overhaul it is how they see it. To them their only choice is Trump. You cannot persuade such people. You might not even succeed at making their lives better but you might have better luck with their children if you can find a way to educate them well.
For those who are informed and bother to think through the issues they will conclude that Trump talked no sense. If they do not support Clinton then the objection is not with her experience and competence and to their perception of her character.
Americans are idealistic and to be around the block too long is not an asset when you offer yourself to voters because they can't imagine you in fairy tales they all love. Obama had that advantage as the shiny new thing in 2008. Some of these idealists will gravitate to Gary Johnson. This is Clinton's loss.
Therefore the game from now till November 8 is to leave the Trump supporters alone and get those who are undecided to vote Clinton. I am with her because I am a realist and also I am completely unlike the sort who are supporting Trump. The other group to persuade are those who find modern day issues too complex for them to sufficiently understand and are withholding support from Clinton because they thought she isn't honest. They are not giving their vote to Trump either because the man in temperamentally and morally unfit to to be commander in chief.
We have 50/50. There are practically no average American. He or she is either smart or dumb. Most of the smart ones are immigrants or children of immigrants. The dumb ones had been immigrants once but generations removed. That is why they want to go back to the Great America they remember which is fantasy than reality. It is a world which Obama painstakingly pointed out to them didn't exist, besides the world is moving on with or without America.
Update: Sep 28 9:45 am
I think it is really worth reading Elizabeth Drew's explanation in Project Syndicate: Why is the US Presidential Race So Close?