Democratic nominee Hillary Clinton beat Republican rival Donald Trump 52 per cent to 39 per cent in Wednesday night's final presidential debate.
According to a CNN/ORC poll of debate watchers, there was a plus or minus 4 percentage point margin of error.
The sample of debate watchers were 36 per cent Democratic and 29 per cent Republican, making them slightly more Democratic than an average poll of all Americans.
Trump did outperform expectations. Nearly 6 in 10 viewers said he did better than expected, whereas 44 per cent said the same of Clinton, the poll showed.
The 90-minute debate that took place at University of Nevada's Thomas and Mack Centre comes 20 days ahead of the November 8 election, was moderated by Fox News journalist Chris Wallace.
Meanwhile, Trump expressed satisfaction with his performance in the last presidential debate.
"That was really exciting. Made all of my points. 'Make America Great Again'," tweeted Trump minutes after debate ended.
The candidates thrashed out issues from abortion rights to gun control to the battle against the Islamic State.
They clashed on matters of policy -- foreign and domestic. They even differed on whether they would accept the results on November 8, with Trump saying he would "take a wait-and-see approach" and Clinton calling that "horrifying", reported ABC News.