US President Donald Trump and his White House challenger Joe Biden clashed over Covid and race while trading corruption charges, in their final live TV debate.
On the pandemic, Mr Biden would not rule out more lockdowns, while Mr Trump insisted it was time to reopen the US.
Mr Trump cited unsubstantiated claims Mr Biden personally profited off his son's business dealings. The Democrat brought up Mr Trump's opaque taxes.
Mr Biden has a solid lead with 11 days to go until the presidential election.
But winning the most votes does not always win the election, and the margin is narrower in a handful of states that could decide the race either way.
More than 47 million people have already cast their ballots in a voting surge driven by the pandemic.
This is already more than voted before polling day in the 2016 election. There are about 230 million eligible voters in total.
What was the overall tone?
Thursday night's primetime duel in Nashville, Tennessee, was a less acrimonious and more substantive affair than the pair's previous showdown on 29 September, which devolved into insults and name-calling.
Following that political brawl, debate organisers this time muted microphones during the candidates' opening statements on each topic to minimise disruption.
But the 90-minute debate, moderated by NBC's Kristen Welker, saw plenty of personal attacks between the opponents, whose mutual dislike was palpable.
In their closing argument to voters, they offered starkly different visions for the nation on everything from shutting down the country to tackle coronavirus, to shutting down the fossil fuel industry to confront climate change.
Coronavirus 'going away'
Nowhere was the distinction between the two candidates more apparent than in their approach to the pandemic.
Asked about his support for more lockdowns if the scientists recommended it, Mr Biden, a Democrat, did not rule it out.
But Mr Trump, a Republican, said it was wrong to inflict further damage on the economy because of an infection from which most people recover.
"This is a massive country with a massive economy," said the president. "People are losing their jobs, they're committing suicide. There's depression, alcohol, drugs at a level nobody's ever seen before."
Mr Trump, 74, declared that the virus was "going away" and that a vaccine would be ready by the end of the year, while Mr Biden warned the nation was heading towards "a dark winter".
The president said: "We're learning to live with it." Mr Biden, 77, countered: "Come on. We're dying with it."
Mr Biden laid blame for the 220,000-plus American deaths from the pandemic at Mr Trump's door.
"Anyone who's responsible for that many deaths should not remain president of the United States of America," he said.
'This guy is a dog whistle'
During a back and forth on race relations, Mr Trump said: "I am the least racist person in this room."
He brought up the 1994 crime bill that Mr Biden helped draft and which Black Lives Matter blames for the mass incarceration of African Americans.