Vice President Joe Biden and Republican Paul Ryan, the man who wants his job, exchanged fire over taxes, Medicare, national security and some animated facial expressions in their only debate before Election Day.
Here are five things we learned from Thursday night:
1. Biden brought it
We expected Ryan, not Biden to bring a three-ring binder full of facts and figures to the debate. It's not that the data-driven Ryan didn't show up with an arm full of his statistics; it is just that Biden did so as well.
And Biden's aggressive offense from the very beginning drowned out Ryan until about 45 minutes into the debate.
Biden's 36 years in the Senate served him well Thursday night. Who says that delivering hundreds of floor speeches on Capitol Hill isn't useful? The vice president also proved wrong the critics, who predicted he was going to make a gaffe. He didn't.
In many ways, Biden stole a page from Mitt Romney's debate playbook: put your head down, charge forward and don't stop. Romney effectively employed this strategy last week and Barack Obama was never able to recover. While Ryan put up a fight last night, he, too, was unable to regain his footing.
An Obama-Biden campaign official said before the debate that the vice president's goal was to try and compare and contrast the two competing campaign's vision for the future. Whether you agree or disagree with the specifics of the Obama-Biden or Romney-Ryan plans, Biden did a better job of selling his last night.
It will be several days until we know if this debate has helped the Obama-Biden campaign stem the political bleeding. But Biden did what he needed to do.
2. Too much Joe?
If Biden was on a mission to bring the fight to Ryan, then it appeared to be mission accomplished for the vice president.
Moments into the debate, Biden went on the attack.
"On Iraq, the president said he would end the war. Gov. Romney said that was a tragic mistake," said Biden.
Minutes later the vice president pushed back against criticism by the Wisconsin congressman, saying "not a single thing he said is accurate."
And he called other accusations by Ryan "a bunch of stuff."
Biden went where President Barack Obama wouldn't last week in his debate with Romney, bringing up Romney's "47%" controversy as well as the Republican nominee's tax rate.
And later, when Ryan discussed President John F. Kennedy's tax policies, Biden fired back: "Oh, now you're Jack Kennedy?"
"The vice president came and showed fight. He showed his boss what it is to engage and engage and engage and attack and attack and attack," said CNN Chief National Correspondent John King.
"I think Joe Biden did do his boss a lot of help," agreed Senior CNN Political Analyst David Gergen, who's advised both Democratic and Republican presidents.
But was Biden too aggressive?
"I think Joe Biden is an authentic person. He speaks his mind. People know him. They expect that," Obama senior adviser David Axelrod said. "I think that authenticity is something that people appreciate."
The Romney campaign disagreed.
"The sighing, the eye-rolling, the grinning. I don't know if the vice president knew that there was a camera on him the whole time, that there was a split screen," senior Romney campaign adviser Russ Schriefer said. "Even if we thought he was making good points, I think that they stepped on his good points. He was trying to cram everything in that he could that wasn't in the last debate to try and get it all out at once. But I don't think he made any kind of coherent argument as to why the Obama-Biden ticket should be re-elected."
Gergen agreed: "On style I think that Paul Ryan won the debate. The Biden dismissive laughs, the interruptions, the sort of shouting, I think that Ryan was calmer and frankly more presidential."
What did debate watchers think? Seven out of 10 debate watchers in a CNN/ORC International poll said that Biden was the aggressor.