I think Kamala "won" the debate in the sense that she exceeded expectations, appeared plausibly presidential, and was disciplined enough to carry the night. But long term, I think Trump scored the points that will be the most remembered: the country is going to hell, it's your fault, etc.
On the other hand, I don't think Trump did anything to assuage the fears that undecideds probably have about his being mentally unhinged and narcissistic. So in the end I think the race is basically unchanged.