PARIS - Socialist candidate Francois Hollande appeared to solidify his chances at winning France's presidency Thursday after his strong showing in a debate against beleaguered incumbent Nicolas Sarkozy.

Hollande also won the support of a prominent centrist who came in fourth in the first round of presidential elections.

The conservative Sarkozy has trailed Hollande throughout the campaign in the polls and needed a knockout performance in Wednesday night's debate. Pollsters said the mild-mannered Hollande was surprisingly resilient in the bitter back-and-forths with his longtime rival.

"Now the campaign is pretty much finished," said Gael Sliman, a pollster at BVA agency. "With the exception of a completely unforeseen catastrophe in the next 48 hours, Francois Hollande is going to win the presidential election in France."

The result of the runoff will set the course for the next five years for France, a nuclear-armed country with a permanent seat on the U.N. Security Council. It could reshape the debate in the 17-nation eurozone - which Sarkozy has helped guide along with Germany's Angela Merkel - on how best to resolve the European debt crisis amid sluggish growth across the continent.

Centrist leader Francois Bayrou dealt Sarkozy a new blow Thursday night. Bayrou said he would not give his voters specific guidance for Sunday's vote - but that he will cast a ballot for Hollande.

"The vote for Francois Hollande, that's the choice I am making," he said, criticizing Sarkozy's anti-immigrant rhetoric as too "violent."

Sarkozy kept it up anyway Thursday at a big campaign rally in Toulon.

"We don't want different tribes, we don't want ethnic communities to turn in on themselves, we don't want [noncitizen] immigrants to vote," he said. He is seeking support from the far-right voters who gave anti-immigrant party leader Marine Le Pen a strong showing in the first round of elections.

Critics of Sarkozy have often faulted him for his brash style, alleged chumminess with the rich, and inability to reverse France's tough economic fortunes.