Former French prime minister Francois Fillon took a strong lead in the first round of the rightwing presidential primary Sunday but ex-president Nicolas Sarkozy risks elimination, partial results showed.

In a major surprise, Fillon had 42.8 percent of the vote to 26 percent for former prime minister Alain Juppe and 24.4 percent for Sarkozy, according to tallies from one third of polling stations.

Only the top two candidates progress to next week's run-off.