Far-right candidate Marine Le Pen won 18.2 to 20 percent in today's first-round of the French presidential election, official estimates said, the highest ever score for her anti-immigrant party.

The estimate after polls closed at 8:00pm was higher than previous party leader Jean-Marie Le Pen's 2002 score of 17 percent that allowed him to go through to the run-off, and was double his 10 percent in 2007.

"I passed her the baton, she runs faster than me, then so much better," Le Pen senior, who handed the reins of the party to his daughter last year, told France 2 television, but he denied that he had been "eclipsed".

Socialist challenger Francois Hollande is to face right-wing incumbent Nicolas Sarkozy on May 6 after both men made it through to the run-off, with Hollande slightly ahead.

Sarkozy is expected to try to appeal to far-right voters to win the second round.