Newly-promoted Monaco beat Lorient 1-0 Sunday to return to the top of the table.
Radamel Falcao won and converted a penalty in the sixth minute for his fourth goal of the season. The Colombia striker had been tripped by Lorient goalkeeper Fabien Audard.
Lorient offered little in attack all match. Sadio Diallo thought he had equalised in the 26th minute but his effort was ruled out for offside.
Monaco moved back to top spot, a point ahead of Saint-Etienne and two ahead of defending champion Paris Saint-Germain. Monaco have won four of their first five matches.
Elsewhere, Lille slipped to their first home defeat since March as they lost 2-0 against Nice.
The visitors scored with their first chance of the match in the 20th minute, when Christian Bruls backheeled Gregoire Puel's cross on for Dario Cvitanich to drill into the right corner.
Cvitanich doubled his team's tally on the stroke of half-time. Lille lost the ball and Bruls set off on a counter attack, down the right flank before picking out Cvitanich, who drove an angled shot into the opposite corner.
Lille almost got straight back into the game after the break but Nice goalkeeper David Ospina pulled off a double save to deny Franck Beria and Ronny Rodelin before Salomon Kalou saw an effort crash off the right post.
Rennes secured a 0-0 draw at Lyon in the evening match. The visitors had come to play for the draw and offered little in attack, focusing on defense.
Lyon had 11 shots in the second half alone and Bafetimbi Gomis saw an effort crash off the crossbar in the 67th minute. Rennes are fifth, a point above Lyon.