Paris ( CNN ) -- Francois Hollande defeated French President Nicolas Sarkozy in a presidential runoff Sunday , signaling a shift to the left as the country and Europe fight to dig out of a weak economy . In a victory speech to supporters in Tulle , Hollande declared his win `` a great date for our country , and a new start for Europe . '' The Socialist challenger promised to govern for all of France . `` Many people have been waiting for this moment for many long years . Others , younger , have never known such a time . ... I am proud to be capable to bring about hope again , '' he told the cheering crowd . `` Tonight , there are not two Frances . ... There is only one France , only one nation that is united with the same destiny , '' Hollande said . The president-elect , who will be the nation 's first left-wing president since Francois Mitterrand left office in 1995 , suggested there was a sense of relief in many European countries because of his win . `` Austerity can no longer be something that is inevitable , '' he said . Later , Hollande went to Paris , where he addressed a large crowd at the Bastille . Supporters waved flags and shouted his name . `` I know what many people feel -- years and years of wounds , of ruptures , and we have to repair , recover , unite . That is what we 're going to do together , '' he vowed . Hollande congratulated Sarkozy , who earlier conceded to Hollande as results from exit polls and official tallies in the runoff election came in . `` I carry the entire responsibility for this defeat , and I 'm going to say why . I fought for the values of responsibility , and I 'm not a man who does not accept his responsibilities , '' Sarkozy said from his Paris campaign headquarters , as members of the crowd shouted , `` No ! '' `` I 'm ready to become a French person amongst French people , and more than ever I have the love for my country deeply ingrained in my heart , '' Sarkozy said . With almost all of the votes counted , Hollande was leading with 51.6 % to Sarkozy 's 48.4 % , the nation 's Interior Ministry said . Voter turnout was reported at more than 80 % . Exit polls said Hollande won 51.9 % of the vote , France 2 television reported . Crowds roared at the center-left candidate 's campaign headquarters as the exit poll results came out Sunday evening . Celebratory car horns blared along the Champs-Elysees in Paris . `` It 's a great night , full of joy for so many young people all across the country , '' said Thierry Marchal-Beck , president of the Movement of Young Socialists . U.S. President Barack Obama called Hollande shortly after results were in to congratulate the newly elected president and invite him to the White House . Sarkozy had fought to keep his job amid a wave of discontent over his inability to rein in unemployment . He defended his economic record despite low growth and unemployment at about 10 % , saying the impact of Europe 's debt crisis could have been far worse . France is a key player in plans to lead the eurozone out of its debt crisis , making the election vital to the region . Sarkozy 's defeat marks the latest -- and most significant -- of at least half a dozen European leaders swept from office during the eurozone economic crisis , including the Greek and Italian prime ministers . France 's vote came the same day as the Greek parliamentary election . Exit polls in that country indicated Greece 's ruling coalition appeared headed for steep losses , while parties on the far left and far right were poised to make significant gains amid anger over austerity measures . Hollande and Sarkozy traded insults last week in the only televised head-to-head debate of the campaign . Sarkozy labeled Hollande a liar and a `` little slanderer , '' while Hollande accused the president of shirking his responsibilities , cronyism and favoring the privileged over France 's poor . Both candidates reached out to France 's undecided voters since the first-round vote on April 22 left them the only two standing . Centrist Francois Bayrou , who took 9 % of the first round vote , delivered a boost to Hollande 's campaign Thursday when he said he would vote for the Socialist and urged his supporters to vote according to their conscience . Sarkozy has been president since 2007 . CNN 's Jim Bittermann , Hala Gorani , Saskya Vandoorne and Stephanie Halasz contributed to this report .
NEW : President-elect Francois Hollande addresses a large crowd of supporters in France . NEW : With nearly all of the ballots counted , he leads with 9 % of the vote . Stephanie Halasz declares his victory `` a new start for Europe '' President Francois Hollande concedes , saying he carries the responsibility for the defeat .