Centrist Emmanuel Macron will enter the second round of voting as a clear favourite over his rival, the anti-immigration leader Marine Le Pen.
- Profile: Who is Emmanuel Macron?
- Profile: Who is Marine Le Pen?
- What you need to know about the French election
- 'Anti-fascists' clash with Paris police after vote
- How the world of politics reacted to the result
Pro-European centrist Emmanuel Macron and anti-immigration leader Marine Le Pen began a final duel for the French Presidency on Monday after a first round of voting delivered a stunning blow to the traditional political class.
Macron is clear favourite to become France's youngest president after topping Sunday's ballot with 23.75 per cent of votes, slightly ahead of National Front (FN) leader Le Pen on 21.53 per cent, according to final results.
"For months and again today I've heard the doubts, the anger and the fears of the French people. Their desire for change too," 39-year-old Macron told thousands of flag-waving, cheering supporters in Paris on Sunday.
WATCH: Macron puts Le Pen in his sights
He pledged to unite "patriots" behind his agenda to renew French politics and modernise the country against Le Pen and "the threat of nationalists" as mainstream political leaders urged voters to back him and keep the far-right away from the Elysee Palace.
Polls suggest the ex-investment banker would beat Le Pen easily in the second round run-off on May 7, which will not feature a candidate from the traditional left or right for the first time in six decades.
Despite serving as economy minister in the outgoing Socialist government of Francois Hollande, Macron casts himself as a political "outsider", who only recently formed his movement "En Marche!" ("On the move").
"The challenge is to break completely with the system which has been unable to find solutions to the problems of our country for more than 30 years," Macron said, already eyeing crucial parliamentary elections in June.
Amid jubilant scenes at Macron's party, supporter Marie-Helene Visconti, a 60-year-old artist, said the result was "a victory for openness, social-mindedness."
The outcome capped an extraordinary campaign in a deeply divided and demoralised France, which has been rocked by a series of terror attacks since 2015 and remains stuck with low economic growth.
Le Pen, who has hardened her anti-immigration and anti-Europe rhetoric over the past week, hailed a "historic vote" in front of her supporters, adding: "The first stage has been passed."
The French vote was being closely watched as a bellwether for populist sentiment following the election of Donald Trump as US President and Britain's vote to leave the EU.
WATCH: Le Pen hails 'historic' result
Throughout the campaign, Macron insisted France was "contrarian" - ready to elect a pro-globalisation liberal at a time when right-wing nationalists are making gains around the world.
The euro rose sharply as fears of France pulling out of the single currency and European Union receded and traders eyed a Macron win in the second round.
"Most likely, the French election can mark a turning point for France and Europe," said analyst Holger Schmieding from Berenberg Bank.
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Le Pen follows father
Le Pen follows in the footsteps of her father Jean-Marie, who made it through to the 2002 presidential run-off in what came as a political earthquake for France.
Le Pen Senior went on to suffer a stinging defeat when mainstream parties closed ranks to keep him out.
Though Le Pen came in behind Macron, there was joy at the FN's election party Sunday night in Henin-Beaumont, a former coal mining town in northern France, with outbursts of the Marseillaise national anthem.
Le Pen said the second round would be a battle over France's future, with her vision of a France out of the EU and behind reinforced borders radically different from her opponent's.
"The major issue of this election is runaway globalisation, which is putting our civilisation in danger," she told supporters.
Watch: Expats in Australia vote for France's president
"Either we continue on the path of complete deregulation, with no borders and no protection ... mass immigration and free movement of terrorists ... or you choose France," she added.
Far-right expert Nonna Mayer at Sciences Po university said a Le Pen victory was not impossible, "but it seems unlikely that she will carry the second round".
"If she wins, it will obviously be an anti-Europe, protectionist, exclusionist line that wins and which could have troubling consequences for Europe and France," she added.
Despite Macron's plans to "relaunch the building of Europe", the combined scores of staunch eurosceptics Le Pen, far-left Jean-Luc Melenchon and nationalist Nicolas Dupont-Aignan add up to around 46 percent.
Macron also drew immediate support from his defeated rivals from the Socialists and Republicans.
Socialist Benoit Hamon, who won a humiliating 6.35 percent, said the left had suffered a "historic drubbing" but urged voters to keep out Le Pen who he said was "an enemy of the republic".
Scandal-hit Republicans candidate Francois Fillon followed suit, saying: "There is no other choice than voting against the far-right."
Fillon was seen as a favourite until January when his campaign was torpedoed by allegations that he gave his British-born wife a fictitious job as his parliamentary assistant.
He took 19.91 percent of Sunday's vote.
Support for Communist-backed Melenchon, meanwhile, had surged in recent weeks on the back of assured performances in two televised debates.
He got 19.64 percent of the vote, underlining the strength of anti-establishment sentiment.
The vote took place under heavy security after Thursday's killing of a policeman on Paris's Champs-Elysees avenue claimed by the Islamic State group.
With France still under the state of emergency imposed after the Paris attacks of November 2015, around 50,000 police and 7,000 soldiers were deployed to guard voters.
Thursday's shooting was the latest in a bloody series of attacks that have cost more than 230 lives since 2015.
Nearly 47 million people were eligible to vote in the eurozone's second biggest economy and turnout was high at more than 78 percent.
Watch: French voters set for presidential election