US President Joe Biden and Donald Trump have faced off in the first debate in the 2024 presidential election campaign.
The format, with each taking turns to speak with their opponent's microphone muted, was designed to prevent a shouting match with both candidates talking over each other.
There was also no studio audience.
The CNN Presidential Debate saw disagreements on the economy, abortion and their records in office.
President Biden answered all night with a hoarse voice - a potential issue for those questioning if he is too old for the job.
The mediators divided the debate in to subjects, beginning with the economy.
Mr Trump claimed that under his presidency the US had the "greatest economy in the history of our country", only stalling when COVID struck.
Joe Biden hit back saying he inherited "an economy that was in freefall".
"The pandemic was so badly handled... the economy collapsed," he said.
"What we had to do is try to put things back together again. That's exactly what we began to do."
Abortion
On the issue of abortion, Mr Biden described the decision to overturn Roe v Wade as horrendous.
"It's been a terrible thing what you've done," he told Trump.
For his part the former president said it was right for individual states to decide policy on abortion.
Immigration
Next came immigration, previously something of a "trump" card for the former president.
Mr Biden was asked about his record.
"The Border Patrol endorsed me, endorsed my position," he said, before turning on Mr Trump.
"He was separating babies from mothers, putting them in cages, making sure that the families are separated [when he was in office]," he said.
Mr Trump responded: "We have the largest number of terrorists coming into our country right now."
"That's simply not true," Mr Biden said.
"There's no data to support what he said, once again, he's exaggerating. He's lying."
Asked what he will do to address the crisis, Mr Trump said "we have to get them out" but didn't specify any particular policy.
Foreign policy
On Ukraine, Donald Trump was the first to answer, taking aim at Mr Biden's handling of it.
"As far as Russia and Ukraine, if we have a real president, a president that was respected by Putin, then he would have never invaded Ukraine."
Asked what he thought of Mr Trump's comments, Joe Biden replied: "I've never heard so much malarkey in my whole life."
He warned that if Mr Putin wins the war there is a risk he will go after other countries like Poland and Belarus. However the strength of his argument was undermined by appearing to confuse Mr Trump and President Putin at one point.
The Middle East was next, with Biden saying the US had "saved Israel", referencing the ongoing support from his government and the organised defence against a massive Iranian air attack.
Trump however slammed his opponent's handling of the crisis in the Middle East.
"He's become like a Palestinian, but they don't like him because he's a very bad Palestinian. He's a weak one," he said.
Capitol riots
Next came topics where Mr Biden genuinely had the chance to land some heavy blows: the Capitol riots and the litany of criminal cases facing Trump.
The odd punch did hit home but - as throughout the debate - Mr Trump appeared in charge, confident in his own version of the truth.
He repeatedly said he did nothing wrong, claiming any action he encouraged was to be carried out "peacefully and patriotically".
Joe Biden retorted: "He encouraged his folks up on Capitol Hill.
"Now he says if he loses again, [he's] such a whiner, it is basically [going to be] a bloodbath."
The only time Mr Trump appeared even slightly uncomfortable was when Biden pointed out his recent criminal charges and calling him a convicted felon.
"The only person on this stage that is a convicted felon is this man I'm looking at right now," he said of the former president.
Trump 'morals'
In one of his most forceful moments of the debate, Mr Biden referred to Mr Trump's alleged sexual relationship with porn star Stormy Daniels, telling him: "You have the morals of an alley cat."
The debate continued, covering racial inequality, climate change and the US opioid crisis, but in truth the optics varied little.
Donald Trump a chin-jutting picture of arrogance and self belief, Joe Biden often seeming to feel his age, only coming into his own when he lost his temper over what he clearly regarded as his opponent's lies.
The debate revealed little of substance with regard to policy, with podcaster and analyst Tim Miller tweeting that it was 'the worst debate in history'.
Pretty clear that we are witnessing the worst presidential debate on style and substance in the history of our nation tonight.
— Tim Miller (@Timodc) June 28, 2024
The level of the debate was put into sharp relief with the two candidates defending their mental capabilities and squabbling about golf.
Taking a shot at Mr Biden, Mr Trump said the US President "can't hit a ball 50 yards".
Mr Biden replied, saying: "I'd be happy to have a driving contest with him."
President Biden's team say he had a cold and that was the reason for his hoarse voice, stumbling as he spoke and seemingly random topic changes.
Joe Biden
Following the debate some Democrats questioned whether Joe Biden should still be in the running.
It's "time to talk about an open convention and a new Democratic nominee," one Democratic lawmaker told NBC News.
Another said: "This was like a champion boxer who gets in the ring past his prime and needs his corner to throw in the towel." The lawmaker also added that he meant Mr Biden should exit the race.
David Axelrod, a senior aide to former President Barack Obama, told CNN: "There is a sense of shock at how he came out at the beginning of this debate. How his voice sounded. He seemed a little disoriented.
"There are going to be discussions about whether he should continue. Only he can decide if he's going to continue," Mr Axelrod added.
Changing candidates at this stage of the campaign would be difficult and unprecedented.
Unless Joe Biden chooses to step aside, delegates at the Democratic National Convention would have to revolt - despite being elected on their pledge to nominate the president.
Reporting by: IRN