Former President Nicholas Sakozy was Francois Fillon and Alain Juppe in the battle to be the main contender to far-right leader Marine Le Pen, predicted to be one of two who take part in the final round of the French presidential election next May.
With 80% of public votes counted on Sunday night, Francois Fillon, was ahead with 43.9% of public votes, while Alain Juppe ahd secured 27.9%.
Ms Le Pen is campaigning on a pro-nationalist, anti-immigration ticket amid growing fear of Islamist terrorism.
Her rise has been attributed to the same sentiment that prompted Donald Trump’s victory in the US and Brexit in the UK.
Last week she told Sky News that Brexit and Mr Trump’s shock victory were signs of the “emergence of a new world” in which disillusionment with mainstream politics has led many in France to consider her their only hope.
Both men are likely to go into a second round – one of whom is almost certain to be one of the two contenders for the next president.
It is expected that the pair will now face each other again on 27 November.
Pollsters have predicted Mr Juppe would win the primaries and subsequently defeat Ms Le Pen.
The ruling Socialist party, under the current President Francois Hollande, is in disarray, with polls showing he is likely to be eliminated in early voting next year.