Ninety minutes, two commercial breaks and no studio audience.
The stakes were high for a historically early US presidential debate between current president Joe Biden and his predecessor, Donald Trump.
Joe Biden had to show he was up to the job, in the face of mounting concerns about his mental and physical fitness.
Donald Trump had to appear presidential and show Americans he wanted to win back the White House to fight for their interests, rather than airing grievances about the 2020 election and the criminal cases against him.
But neither man exactly lived up to those expectations, with Biden bumbling and Trump blustering.
Here are the key takeaways from round one of Trump v Biden.
1. Biden appears frail and has a brain fade
It's hard to overestimate the amount of angst there was in Democratic circles ahead of this debate about whether Joe Biden could put in a robust performance.
The White House has repeatedly pushed back on reports that the president is slipping mentally.
It's hard to see how the party and the majority of Americans — who, according to polls, think the 81-year-old is simply too old to seek another term — will be reassured by Joe Biden's performance.
Less than 15 minutes in, there was a cringeworthy moment when he appeared to lose his train of thought, trailing off on an answer about health care benefits.
"Making sure that we are able to make every single solitary person… eligible for what I've been able to do with the uh… COVID — excuse me, with dealing with everything we have to deal with… uh… look… if… we finally beat Medicare," the president said before being cut off.
Trump took that opportunity to hit back with: "Well, that's right. He did beat Medicare. He beat it to death."
Joe Biden's voice was raspy and quiet from the outset and he often appeared to struggle to round off his sentences, tripping over his own words.
These are hallmarks of the way the president speaks but are becoming more pronounced with age, and this was a particularly bad night in that regard.
Reporters being briefed by the Biden campaign said they were being told the voice issues were due to a cold.
Those reports didn't start to filter through until the debate was well underway and will likely to be the focus of scrutiny in the wash-up.
In comparison, Donald Trump appeared energetic and his voice was commanding.
He too has had some seniors' moments in recent months, confusing people and dates, but on the whole, he was sharp tonight.
"I really don't know what he said at the end of that sentence, and I don't think he did, either," Trump said at one point about his opponent.
Biden's performance improved a little as time went on, but not enough to reverse an overall impression of frailty.
2. Trump blustered and deflected
It was a more nimble and disciplined Trump than was on display four years ago.
Each candidate had two minutes to answer questions, but Trump often used the beginning of his time to rebut what Biden had said or steer the answer to his pet issues, often the issue of illegal migration on the southern border.
Moderator Dana Bash had to press him several times to try and get an answer on whether he would accept the result of the election.
"If it's a fair and legal and good election, absolutely," the former president said.
He ignored a question about whether Russian president Vladimir Putin's terms for the war in Ukraine were acceptable by talking about veterans' dislike for Biden.
He also tried to avoid directly answering a question about his role in the January 6 attack on the US Capitol.
CNN's up-front rule about not being able to fact-check either candidate's responses in real time also appeared to work to his advantage.
Among his wilder claims, that abortion rights allowed babies to be killed after birth.
3. Alley cats, porn stars and golf handicaps — things got nasty
Muted microphones didn't stop the name-calling.
Biden went on the attack over Trump's criminal convictions, accusing him of having sex with a porn star while his wife was pregnant.
"I didn't have sex with a porn star," Trump responded.
Biden also brought up the civil cases Donald Trump has faced, with a New York jury finding him liable for sexually abusing writer E Jean Carroll.
"You have the morals of an alley cat," Biden fired at his opponent.
As they discussed the issue of Trump reportedly referring to veterans as suckers and losers, Biden also went on the offensive.
His son Beau served in the military, and Joe Biden claims, without evidence, that it was his exposure to a burn pit in Iraq that led to the brain cancer that eventually killed him.
"My son was not a loser. He was not a sucker. You're the sucker. You're the loser."
Trump said the sucker and loser quote was made up.
Trump accused Biden of being the "worst president in the history of our country".
Close to the end of the debate, things descended into the surreal with the two candidates getting into an argument over golf handicaps.
Trump claimed to be still winning club championships.
Biden offered to play him, saying he got his handicap down to a six when he was vice-president.
Trump said that this was Biden's "biggest lie of all".
"I've seen your swing. I know your swing. Let's not act like children," he said.
4. Abortion, immigration and the economy
Trump attacked Biden over the economy, claiming his administration oversaw "the greatest economy in history".
Biden pointed out there were fewer jobs at the end of Trump's term than at the start, but Trump was leaning into what many Americans were feeling.
Despite the macro indicators showing the economy is improving, people are still struggling with increased prices and a sense that they are worse off.
On abortion, Biden attacked Trump for taking credit for appointing the Supreme Court justices who overturned the constitutional right to abortion two years ago and said if he is re-elected, he will work to enshrine the right to abortion into law.
The Democrats' support of reproductive rights was a factor in their better-than-expected performance in the mid-terms and they are hoping it will be a winner again in November.
But even on this question, Biden appeared bumbling at times, and wandered into very odd territory as he tried to counter Trump's claims that migrants crossing the border illegally were raping women.
"There's a lot of young women being raped by their in-laws, by their spouses, brothers and sisters, it's just ridiculous", Biden claimed.
There is no evidence of a spike in crime perpetrated by migrants, but Trump has highlighted a number of recent cases in which women have been raped or killed by people found to be in the US illegally.
Trump several times successfully turned the conversation to the border, hitting Biden on an issue he is seen as vulnerable on.
Biden reminded the audience that Trump torpedoed a bipartisan border bill, but again, his delivery and the nuance of this argument may mean it's lost on many viewers not tuning in to daily politics.
5. The wash-up
There's no denying this debate went badly for the president and the early takes are stinging.
"A debate disaster", headlines the Atlantic.
CNN correspondent John King described it as "game-changing".
"There is a deep, a wide, and a very aggressive panic in the Democratic party', he said.
On MSNBC, David Plouffe, a veteran Democratic strategist who managed Barack Obama's 2008 campaign, called it a "Defcon 1 moment".
"The concern level is quite high", he told the network.
Vice-President Kamala Harris acknowledged President Biden's "slow start", but told CNN "it was a strong finish".
The vice-president said it wasn't about the last 90 minutes, but about the last three and a half years.
The idea of Joe Biden calling it quits at this late stage has been raised before, but generally in quiet, respectful terms.
That's all changed after tonight, and if he does stay it could be very difficult for Joe Biden to turn things around in the next four months.
