CLEVELAND -- A combustible debate Tuesday night between President Trump and Democratic presidential nominee Joe Biden concluded with a fiery exchange over the integrity of the election and ominous warning from the president.

The president – spotlighting his months-long charges that the massive increase in balloting by mail this year due to the coronavirus pandemic – said these ballots are “being sold, they’re being dumped in rivers. This is a horrible thing for our country.”

BIDEN AND TRUMP CLASH IN FIERY PRESIDENTIAL DEBATE

Trump then warned that “this is not going to end well.”

President Donald Trump and Democratic presidential candidate former Vice President Joe Biden exchange points during the first presidential debate Tuesday, Sept. 29, 2020, at Case Western University and Cleveland Clinic, in Cleveland, Ohio. (AP Photo/Morry Gash, Pool) (Associated Press)

The president, repeating past charges, claimed that “as far as the ballots are concerned, it’s a disaster…this is going to be a fraud like you’ve never seen.”

Biden argued that the president’s “trying to dissuade people from voting he’s trying to scare people into thinking it’s not going to be legitimate.”

And the former vice president – speaking to the millions of viewers watching the debate – urged them to “show up and vote. You will determine the outcome of this election.”

Biden stressed that Trump “cannot stop you from being able to determine the outcome of this election.”

The former vice president, spotlighting Trump’s recent refusal to accede to a peaceful transfer of power if he loses the election, emphasized that, “If I win, that will be accepted. If I lose, that will be accepted.”

And he spotlighted that “if we get the votes, it’s going to be all over. He’s going to go. He can’t stay in power.”

The moderator of the debate – ‘Fox News Sunday’ anchor Chris Wallace – then asked both candidates if they would urge their supporters to stay calm and not engage in civil unrest if the counting of votes continues for days after Election Day on Nov. 3.

The president answered that “if it’s a fair election, I am 100% on board. But if see tens of thousands of ballots being manipulated, I can’t go along with that.”

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Biden said he would call on his supporters to stay calm. And looking at Trump, he charged that “he has no idea what he’s talking about it. The fact is I will accept and he will too. You know why. Because once the winner is declared after all the ballots are counted, all the votes are counted, that will be the end of it. That will be the end of it. And if it’s me, in fact fine. If it’s not me, I’ll support the outcome.”