The two US presidential candidates have clashed over jobs, terrorism and race in a bitter television debate.
The attacks turned personal as Republican Donald Trump accused his rival Hillary Clinton of not having the right temperament to be president.
Meanwhile, Mrs Clinton baited Mr Trump by pointing out that he refuses to release his tax returns.
Hillary Clinton forced Donald Trump onto defense over his temperament, refusal to release his taxes and his past comments about race and women during a fiery debut presidential debate Monday — a potentially pivotal moment in a tight election campaign.
“I think Donald just criticized me for preparing for this debate,”
“And yes, I did. And you know what else I prepared for? I prepared to be President. And that is a good thing.”
The New York showdown could be the most watched debate in TV history, with up to 100 million viewers.
Hours before the programme, polls suggested the candidates were locked in a dead heat, adding to the tension between the rivals on stage throughout the debate.