Republican Sarah Palin and Democrat Joe Biden clashed on the economy and Iraq during a lively but polite debate on Thursday, but aimed the most criticism at their rivals at the top of the ticket.
In the only vice presidential debate ahead of the November 4 US election, Mr Biden accused Republican presidential contender John McCain of being "out of touch" on the economic crisis and said he was "no maverick" on crucial issues facing Americans.
Ms Palin said Democratic White House candidate Barack Obama was too partisan to work across party lines to accomplish change and was waving a "white flag of surrender" in Iraq.
Both camps claimed victory in a debate unlikely to dramatically change a White House race that Mr Obama leads. Two polls taken after the debate, by CNN and CBS News, judged Mr Biden the winner, but the CNN poll found a big majority thought Ms Palin did better than expected.
With all eyes on Ms Palin in her national debut in an unscripted format, the 44-year-old Alaska governor turned in a steady and aggressive performance in which she repeatedly attacked Mr Obama and pledged she and Mr McCain would work for the middle-class.
She frequently displayed the folksy style that has become a favourite target of late-night comics. "Aw, say it ain't so, Joe," she told Mr Biden at one point, adding a "doggone it" for good measure.
Mr Biden, 65, also had an emotional moment, choking up when recalling having to raise his two young sons alone after their mother died in a car crash.
As the two strode on the stage, Ms Palin greeted Mr Biden, saying: "Nice to meet you. Can I call you Joe?"
The debate came as Mr Obama solidified his lead in national polls and gained an edge in crucial battleground states as the Wall Street crisis spread.
Mr Biden and Ms Palin said they would work to change current US economic policy to make it more friendly to middle-class workers, but Mr Biden noted Mr McCain had called the fundamentals of the economy strong as the Wall Street crisis broke out.
"That doesn't make John McCain a bad guy, but it does point out he's out of touch," Mr Biden, a Delaware senator, said in the debate on the campus of Washington University in St Louis, Missouri.
Ms Palin said Mr McCain had been talking about the American workforce and said Mr Obama would raise taxes on American workers and small business owners. Mr Obama in fact has called for a middle-class tax cut and would raise taxes only on those making more than €180,000.
"I do respect your years in the US Senate, but I think Americans are craving something new and different," Ms Palin told Mr Biden.
Mr Biden pledged he and Mr Obama would end the war. Mr Obama is an early critic of the Iraq war who has called for a 16-month timeline to withdraw US troops. "Your plan is a white flag of surrender," she told Mr Biden.
The highly anticipated match-up promised more than the usual drama because of curiosity about Ms Palin, a relative unknown who was thrust into instant celebrity when she was selected as Mr McCain's No. 2 in August.
The encounter may have drawn a larger television audience than the 52 million who watched last week's first debate between the presidential candidates.
Mr Biden said the €505.4 billion bailout of Wall Street he voted for, along with Mr Obama and Mr McCain, might force the Democrats to reconsider their promise to double foreign aid.
"The one thing we might have to slow down is a commitment we made to double foreign assistance," he said when asked what programmes might have to be jettisoned because of the financial crisis.
MsPalin said there was nothing she and Mr McCain would have to forego. "There hasn't been a whole lot that I've promised, except to do what is right for the American people," she said. "I don't believe that John McCain has made any promise that he would not be able to keep, either."
Ms Palin's lack of national experience and her hesitant performance in rare media interviews had raised doubts about her readiness and prompted criticism even from some prominent conservatives.
But she said her experience as a governor and as a mayor of tiny Wasilla, Alaska, was her strength as a candidate for vice president. She frequently said she and Mr McCain were a team of mavericks who could change Washington.
"John McCain has been the consummate maverick," she said. "Mr Barack Obama, of course, he's pretty much only voted along his party lines."