Socialist Francois Hollande narrowly beat conservative incumbent Nicolas Sarkozy in the first round of France's presidential race.
With most votes counted, Mr Hollande received 28.6% to 27.1% for Mr Sarkozy, the Interior Ministry said.
The candidates will face each other in the second round on 6 May.
It is the first time a French president running for re-election has failed to win the first round since the start of the Fifth Republic in 1958.
Francois Hollande, 57, vowed to change the direction of Europe if elected and lead an economic revival with greater social justice.
Marine Le Pen surged to 18% - the biggest result for a far-right candidate. The 43-year-old is the daughter of former paratrooper and National Front founder Jean-Marie Le Pen.
Ms Le Pen told cheering supporters that her wave of support was shaking the system of mainstream consensus politics and her party was now "the only real opposition."
Turnout on Sunday was high, at more than 80%.