second election debate between the pair, but both candidates were determined to maintain their momentum with three weeks until polling day.
Obama was barely off stage before he took his campaign circus out to Iowa, the swing state where he launched his extraordinary rise to power in the 2008 Democratic primary, and which both men hope to win on November 6.
Romney, the Republican flag-bearer, headed south from the New York debate to Virginia, a key battleground which had looked to be leaning towards Obama until the pair's first debate on October 3, which the incumbent lost badly.
Meanwhile, the political class was still digesting the repercussions of the latest fiercely and bitterly contested head-to-head, a so-called "town hall" with questions from members of the public.
Neither man did much to conceal his dislike for the other as they stood up and stalked the stage, trading accusations of dishonesty. Both landed blows but, after his poor earlier showing, Obama carried the day.
Ad hoc polls from major broadcasters all gave the Democrat the edge, and his jubilant supporters took to social media to twist the knife. Analysts agreed that the Romney surge had hit a speed bump, leaving the race closely matched.
"The Republicans will be disappointed that Romney didn't put him away, and the Democrats will be reassured that the president is in full press now," said Linda Fowler, a government professor at Dartmouth College.
John Pitney, professor of politics at Claremont McKenna College, said he thought "the president had a much better night than he had in Denver."
"It was close, but I have to give the edge to Obama."
Bouncing back after being pilloried even by his own side for appearing passive and listless during their first encounter in Denver, Obama was a different character on stage at New York's Hofstra University.
In one spellbinding exchange, Obama stared directly at Romney and rebuked him over his criticism of the White House's handling of an attack on the US consulate in Benghazi, Libya on September 11, which killed four Americans.
"The suggestion that anybody on my team ... would play politics or mislead when we've lost four of our own, governor, is offensive," Obama said, wagging his finger at Romney across the stage.
"That's not what we do. That's not what I do as president, not what I do as commander-in-chief," Obama said, in the most memorable clash of one of the most ill-tempered and contentious White House debates ever.
Seeking to recover, Romney instead stumbled, accusing the president of taking days to recognise that the attack, which killed US ambassador to Libya Chris Stevens, was terrorism and not a protest that got out of hand.
Obama snapped back that he had referred to the assault as an "act of terror" a day after the attack, telling Romney: "check the transcript" before fixing his rival with a withering stare and saying: "Please proceed governor."
CNN moderator Candy Crowley performed an on the spot fact-check and called the dispute in Obama's favor -- leaving Romney stuttering awkwardly.
Even before the debate had ended, Democrats seized the moment to question Romney's credentials to serve as commander-in-chief, while conservatives hammered Crowley for what they said was an unfair intervention.
As anger crackled in the debate hall, the candidates were freed from podiums and roamed the floor, often encroaching on each other's personal space, trading charge and counter-charge over economic policy.
Romney's strongest moments came when he delivered stinging indictments of the Obama economy, charging the president with failing to rein in stubbornly high unemployment or cut ballooning deficits.
"The president wants to do well, I understand," Romney said, adopting a sorrowful tone of voice.
"But the policies he put in place have not let this economy take off as it could have.
"If the president were re-elected, we'd go to almost $20 trillion of national debt. This puts us on a road to Greece," he said, before also vowing to stand up to China over its alleged trade and currency abuses.
Obama countered that Romney had invested in companies in China that were pioneers of outsourcing US jobs, saying: "Governor, you're the last person who's going to get tough on China."
When Romney interrupted, asking Obama if his pension scheme included investment in low wage economies abroad, the president openly mocked his wealth, saying: "I don't look at my pension. It's not as big as yours."
The stakes could hardly be higher, both as national polls and the key races in battleground states tightens into a dead heat.