CNN declared Obama the night's winner by a slight edge, a result echoed by CBS.
And while it is still unclear to what extent opinions logged on Twitter reflect the real-world views of US voters (the latest demographic information available indicates higher than average usage among those who are young, black and urban), the latest poll results marry up with online reaction.
The president's searing rebuke to Mitt Romney's plan for defence spending with a reference to horses and bayonets stood out as the defining moment of the third debate, according to Twitter users.
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The comment came after Romney outlined his plans for spending up to $2 trillion on defence should he win the US election, including updating Naval technology and purchasing a number of new ships.
"Our Navy is smaller now than at any time since 1917," he said.
Barack Obama responded: "I think Governor Romney maybe hasn't spent enough time looking at hour our military works".
"You mentioned the Navy, for example, and that we have fewer ships than we did in 1916. Well, Governor, we also have fewer horses and bayonets, because the nature of our military's changed."
The colourful turn of phrase caused traffic to spike on Twitter, with the social networking site recording 105,767 tweets per minute at 9.45pm, the time the comment went to air.
The comment earned both mockery and serious debate over defense spending.
The second-largest spike was caused by debate moderator Bob Schieffer, whose comment “I think we all love teachers,” earned 102,339 tweets per minute.
Mitt Romney's biggest spike returned 87,040 tweets per minute. It came as the former Governor of Massachusetts took aim at what he referred to as Barack Obama's “apology tour” of Middle East nations earlier in his presidency.
He accused Obama of “going to various nations in the Middle East and criticising America”.
Twitter's official Political Index, which measures users' feelings towards the candidates, gave Mitt Romney an early lead, but later found Obama have resonated more strongly with users of the social media site, by a measure of 44 to 26.
Far from being ignored by Twitter users, Mitt Romney and his comments have provided fodder for pundits looking to make light of the debates.
The US election debate series saw a whole range of Mitt Romney-themed internet memes pop up almost in real time.
The tendency of Twitter users to focus on awkward comments such as Mitt Romney's “binders full of women” or “I like Big Bird” to define whole election debates has been slammed by some as trivialising crucial elements of the US election race.
