Centrist Emmanuel Macron and far-right leader Marine Le Pen are set to face each other in a May 7 runoff for the French presidency after coming first and second in the first round of voting overnight.

Key points: Macron won 23.75 per cent of vote with Le Pen slightly behind at 21.53 per cent

Macron won 23.75 per cent of vote with Le Pen slightly behind at 21.53 per cent Other top candidates Francois Fillon and Jean-Luc Melenchon were eliminated

Other top candidates Francois Fillon and Jean-Luc Melenchon were eliminated Le Pen lauds 'historic result' as Macron vows to fight nationalism

In a race that was too close to call up to the last minute, Mr Macron, a pro-European Union ex-banker and economy minister who founded his own party only a year ago, won the first round with 23.75 per cent of the vote.

Ms Le Pen, leader of the anti-immigration and anti-EU National Front, came in second with 21.53 per cent.

"In one year, we have changed the face of French politics," Mr Macron said in a victory speech after the vote.

Conservative candidate Francois Fillon and far-left contender Jean-Luc Melenchon both came up with roughly 20 per cent, meaning they were eliminated from the presidential race.

The result means that France will see a face-off between politicians with radically contrasting economic visions for a country whose economy lags behind that of its neighbours and where a quarter of young people are unemployed.

Protesters angry that Ms Le Pen was advancing to the second round scuffled with police in Paris.

Protesters angry that Ms Le Pen is advancing scuffle with police in Paris. ( AP: Kamil Zihnioglu )

Crowds of young people, some from anarchist and anti-fascist groups, gathered on the Place de la Bastille in eastern Paris as results were still coming in.

Riot police surrounded the area and tear gas was fired to disperse the increasingly rowdy crowd.

Le Pen praises 'historic result'; Macron to fight nationalism

Sorry, this video has expired Marine Le Pen says she will defend France against globalisation

Following early vote counts, Ms Le Pen celebrated the "historic result" with her supporters while vowing to defend France against "rampant globalisation".

"This result is historic. It puts on me a huge responsibility to defend the French nation, its unity, its security, its culture, its prosperity and its independence," Ms Le Pen told supporters.

"The main thing at stake in this election is the rampant globalisation that is endangering our civilisation," she added, urging French voters to shake off the shackles of an "arrogant elite".

She later went on to launch the opening salvos of the final round, calling Mr Macron "weak" on terrorism.

"I'm on the ground to meet the French people to draw their attention to important subjects, including Islamist terrorism to which the least we can say Mr Macron is weak on," Le Pen told reporters.

Mr Macron also addressed his supporters after the results, calling on all "patriots" to rally behind him against the "nationalist threat".

"I want to be the president of patriots against the threat of nationalists," Mr Macron told a cheering crowd.

Mr Macron, whose "En Marche!" party is only one year old and has never taken part in any parliamentary election, also said he would work on building a parliament majority to be able to govern after legislative elections in June.

He went on to say he would bring in new faces and talent to transform a stale political system if elected.

Sorry, this video has expired Emmanuel Macron bills himself the "patriots' candidate"

Fillon gives support to Macron after conceding defeat

French politicians on the left and right were quick to urge voters to block Ms Le Pen's path to power in the May 7 runoff, saying her virulently nationalist anti-EU and anti-immigration politics would spell disaster for France.

"Extremism can only bring unhappiness and division to France," defeated conservative candidate and former prime minister Mr Fillon said.

"As such, there is no other choice than to vote against the extreme right. I will vote for Emannuel Macron."

Mr Fillon had consistently been polling third in surveys leading up to the election.

French Prime Minister Bernard Cazeneuve called on voters to support Mr Macron, while German Foreign Minister Sigmar Gabriel said he was confident Mr Macron would "put right-wing radicalism in its place".

Though Mr Macron, 39, is a comparative political novice who has never held elected office, opinion polls in the run-up to the ballot have consistently seen him winning the final clash against the 48-year-old Ms Le Pen.

That in turn reduces the prospect of an anti-establishment shock on the scale of Britain's vote last June to quit the EU and the election of Donald Trump as US President.



Supporters in Paris of French presidential candidate Emmanuel Macron. ( Reuters: Philippe Wojazer )

Mr Macron favours gradual deregulation measures that will be welcomed by global financial markets, while Ms Le Pen wants to ditch the euro currency and possibly pull out of the EU.

Whatever the outcome on May 7, it will mean a redrawing of France's political landscape, which has been dominated for 60 years by mainstream groupings from the centre-left and centre-right, both of whose candidates faded.

The final outcome on May 7 will influence France's standing in Europe and the world as a nuclear-armed, veto-wielding member of the UN Security Council and founding member of the organisation that transformed itself into the European Union.

Thousands of security officers patrolled French polling stations. ( Reuters: Pascal Rossignol )

Reuters/AP