The pair swapped insults in Wednesday's tense exchange without either dominating, but Socialist challenger Hollande had gone into the televised clash as the pollsters' favourite and appeared to emerge from it unscathed.
Political observers said they had been surprised by the ferocity of the debate, but doubted it would swing the election far in either direction.
With just days to go before Sunday's run-off and the right-wing incumbent having trailed in opinion polls for more than six months, he did not hesitate to go on the attack, calling Hollande a "liar" and "arrogant" several times.
Hollande's response was just as fierce and sometimes mocking, accusing Sarkozy of refusing to take responsibility for his record and accusing him of self-satisfaction in a period of grim economic crisis for many voters.
"Whatever comes along, whatever happens, you're always satisfied," Hollande declared, after an early exchange on the economy. "That's a lie! A lie!" retorted Sarkozy. "This is not a little joke competition."
Hollande bridled at being called a liar, but quickly regained his composure, saying: "It's obviously a theme I should find intolerable, but coming from your mouth it just becomes repetitive."
Tempers flared again when Hollande accused Sarkozy of stuffing senior posts in government, the media and industry with political cronies and the president responded by calling him a "little slanderer".
"Mr Hollande, you have spoken, doubtless in order to be unpleasant to me, of a 'normal president'. I tell you that the office of president is not a normal office and the situation we are in is not a normal situation," Sarkozy said.
"Your normality is not up to the task at hand," he declared.
Sarkozy denied having been a divisive figure, insisting that there had been no violence and no mood of "civil war" during his first five-year term.
Sarkozy also cited Dominique Strauss-Kahn, the disgraced former IMF chief and senior member of Hollande's Socialist Party, accusing his opponent of washing his hands like "Pontius Pilate" amid rumours of sexual excess.
Hollande fiercely denied this, insisting he had no information about his former ally's private life, and matched Sarkozy blow-for-blow in the debate, ceding nothing and accusing him of making the rich richer and the poor poorer.
"You're not capable of developing a line of reasoning without being rude," Hollande said, later adding: "Me, I will protect the children of the republic. You, you protect the most privileged."
When Sarkozy accused Hollande of "cowardice" in allowing his allies to make dishonest and abusive attacks on his person, the challenger scoffed: "You'll have a hard time passing yourself off as a victim or a lamb."
The political scientist Emmanuel Riviere of pollster TNS-Sofres declared the debate "more or less a draw" but added this represented in effect a victory for Hollande, who as frontrunner just needed to avoid a mistake.
"The Socialist candidate understood this after a while, and relaxed, knowing that he'd landed some blows," he said. "Francois Hollande was not deflated, which was what Nicolas Sarkozy was counting on."
"We haven't seen a debate of that quality since 1988," Gael Sliman of the BVA polling institute told AFP, referring to a notoriously bitter clash between Francois Mitterrand and Jacques Chirac.
A unscientific instant poll of readers of the daily Le Parisien's website showed Hollande as the victor, but most experts said it was too soon to know what undecided voters would make of either candidate's aggression.
Before the debate, polls showed Hollande as the favourite to win in Sunday's run-off vote after he came out slightly ahead of Sarkozy in an April 22 first round that saw eight more candidates eliminated.
The latest surveys forecast that Hollande will win around 54 per cent of the vote to Sarkozy's 46 per cent, figures that have scarcely budged in six months of often intense campaigning.
In the 10 days since the first round, Sarkozy has sought to woo the nearly 18 per cent of voters who backed Marine Le Pen of the anti-immigrant National Front -- a record result for the far right.
He scored some points off Hollande when the pair debated immigration, with his opponent vague on some of the aspects of his plans, while the Socialist was strong on the economy, hammering the incumbent on unemployment.
"Our unemployment has risen, our competitiveness has worsened and Germany is doing better than we are," Hollande said, slamming Sarkozy's economic record.
"Why is Germany doing better than us? Because Germany has done the opposite of the policies you are proposing to the French people," Sarkozy hit back.
"With you it's very simple. Nothing is ever your fault," Hollande said.
Both 57-year-old political veterans will hold another major rally each before the campaign comes to an official end at midnight on Friday, then France's 44 million voters will be called to the polls on Sunday.
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