Francois Hollande was elected France's first Socialist president in nearly two decades on Sunday, dealing a humiliating defeat to incumbent Nicolas Sarkozy and shaking up European politics.
The result will have major implications for Europe as it struggles to emerge from a financial crisis and for France, the eurozone's second-largest economy and a nuclear-armed permanent member of the UN Security Council.
Hollande, a 57-year-old center-left moderate, won the vote with between 52 and 53 percent, according to several estimates, becoming France's first Socialist president since Francois Mitterrand left office in 1995.
Joyful crowds were gathering in Hollande's adopted hometown of Tulle and in front of Socialist headquarters in Paris, as rumors of the result spread more than an hour before French media were legally permitted to publish results.
Three polling institutes - CSA, TNS Sofres and Ipsos - estimated that Hollande had won 52 percent of the vote to Sarkozy's 48, based on samples of actual ballots taken before the official end of polling at 8 p.m. (1800 GMT).
Harris Interactive estimated the Socialist's score at between 52.7 and 53.3 percent. All the estimates were in line with previous opinion polls, which were banned from publication in France from midnight on Friday.
Hollande, who led in the polls throughout the campaign, won the April 22 first round with 28.6 percent to 27.2 percent for Sarkozy - making the right-winger the first-ever incumbent to lose in the first round.
Grey skies and rain showers greeted voters across much of France, but turnout was high, hitting 71.96 percent at 5 p.m. (1500 GMT) according to interior ministry figures. More than 46 million people were eligible to vote.
The election was marked by fears over European Union-imposed austerity and economic globalization, and Hollande has said his first foreign meeting will be with German Chancellor Angela Merkel - the key driver of EU budget policy.
The Socialist has vowed to renegotiate the hard-fought fiscal austerity pact signed by EU leaders in March and to make it focus more on growth, but is facing resistance from Merkel.
The French vote coincides with an election in Greece, where voters were also expected to punish the incumbent parties for landing the country in its bleak economic state.
Anger over sputtering economies has brought down leaders from Ireland to Portugal since the debt crisis washed over the European continent.
Hollande has said he will move quickly to implement his traditionally Socialist tax-and-spend program, which calls for boosting taxes on the rich, increasing state spending and hiring some 60,000 teachers.
Sarkozy fought a fierce campaign, saying a victory for Hollande would spark market panic and financial chaos and calling him a "liar" and "slanderer" in the final days of the race.
But Sarkozy failed to overcome deep-rooted anger at meager economic growth and increasing joblessness, and disappointment after he failed to live up to the promises of his 2007 election.
Sarkozy, 57, was also deeply unpopular on a personal level, with many voters turned off by his flashy "bling bling" lifestyle - exemplified by his marriage to former supermodel Carla Bruni - and aggressive behavior.
Hollande has vowed to be a "normal president" in contrast with Sarkozy, but some have raised concerns over his lack of experience.
Hollande, a long-time Socialist party leader and local lawmaker from the central Correze region, has never held a top government post.
The first round of the election last month was marked by a record score for Marine Le Pen of the far-right, anti-immigrant and anti-Europe National Front, when she took nearly 18 percent of the vote.
Sarkozy turned increasingly to the right ahead of the run-off - vowing to restrict immigration and "defend French values" - but Le Pen refused to call on her supporters to back him and she cast a blank ballot.
Hollande won the backing of centrist Francois Bayrou, who took nine percent in the first round, and Communist-backed Jean-Luc Melenchon of the Left Front, who took 11 percent.
Hollande is expected to be sworn in by May 15 and after seeing Merkel will quickly set off for a series of international meetings, including a G8 summit in the US on May 18-19 and NATO gathering in Chicago on May 20-21.
The Socialists, Sarkozy's right-wing UMP and France's other political parties will now be focused on a parliamentary election to be held over two rounds on June 10 and June 17.