German Chancellor Gerhard Schroeder and his conservative rival Angela Merkel have clashed over the economy in a TV debate ahead of the 18 September poll.
A snap survey indicates Mr Schroeder was judged the winner, but analysts say he failed to deliver a knock-out blow.
Mrs Merkel's Christian Democrats (CDU), well ahead in the polls, have centred their election campaign on Germany's sluggish growth and high unemployment.
Mr Schroeder hit back, saying Germany had become the world's top exporter.
He also highlighted his opposition to the US-led war in Iraq.
Tussle over reforms
During the only televised head-to-head debate in the run-up to the election, the chancellor said his foreign policy had "positioned Germany abroad as a middle-sized power for peace".
He also called on German voters to trust his economic policies, which he said were "aimed at readjusting the social security systems neglected in the 90s".
But Mrs Merkel, who appeared more combative than expected, argued that Mr Schroeder's controversial reforms had been hampered by his own party, the Social Democrats (SPD).
The high unemployment rate tops the election agenda
"Germany can only be a strong, reliable party in the world if we are also economically strong, and that is where we are lacking," she said.
"And, unlike the chancellor, I can be sure with my party colleagues that we will support this course of modernisation together."
Mrs Merkel said the country needed bold steps to revive the country's struggling economy, after seven years of failed leadership.
"You can't be satisfied with the situation in our country," she said. "We have five million unemployed people. It's not like the sun rises and more and more jobs appear.
"No, no, Mr Schroeder. And if you don't have an answer to this question - then nothing will happen. But nothing will happen with this government anyway because you won't get another chance."
Analysts said that while the debate was unlikely to affect the outcome of the election, it might determine whether the coalition Mrs Merkel is hoping to form with the Free Democrats will win enough votes to have a governing majority.
The debate was watched by close to half the nation's voters.
Mr Schroeder dismissed Mrs Merkel's arguments, saying she wanted to use Germans as guinea pigs in an economic experiment.
"What you're saying can't work and what you're saying about growth ignores the fact that we have made Germany the world's leading exporter," he said. "This is thanks to our reforms, our corporate tax policies.
"When you and Helmut Kohl were governing Germany, you were not successful."
Germany's top-selling newspaper, Bild, hedged its bets after the debate, with a headline that asked: "Man Against Woman - Who Was Better?"