Reigning champions Lyon continued their shaky start to the season with a 1-1 draw at home to fellow early strugglers Auxerre, Strasbourg edged a five-goal thriller against Ajaccio and Guingamp were on the wrong end of a 4-2 result in Corsica against Bastia.
Didier Drogba gave Marseille the lead against Le Mans after just 13 minutes and French international Steve Marlet scored his first goal since his season-long loan move from Fulham on the 24-minute mark.
Egyptian striker Mido weighed in with a brace and Dmirti Sychev added a fifth as Alain Perrin's side signalled their intent to lift the title this season, and confirmed Le Mans' status as relegation candidates.
Monaco headed for a crunch game with third-placed Lille as league leaders, and opened the scoring a minute before half time through Ludovic Giuly.
Lille, however, showed their added resilience this term and levelled the scores through Vladimir Mantchev on 76 minutes to grab a point and hold up Didier Deschamps' early title charge.
Champions Lyon played host to Auxerre as both sides looked for a morale-boosting win to give their campaign a kick-start as both have struggled so far.
Prolific marksman Djibril Cisse gave Guy Roux's visitors the lead on 29 minutes only for former Bayern Munich man Giovane Elber to level matters four minutes before half time and grab a share of the spoils for Paul Le Guen's side.
On-loan Liverpool midfielder Alou Diarra gave Bastia the early advantage after 16 minutes of their home match with Guingamp, and Ben Saada doubled their lead on 36 minutes.
Nicolas Gousse pulled one back for the visitors a minute after the interval but a Frederic Nee brace helped Bastia to the victory either side of a Christophe Le Roux penalty.
Danijel Ljuboja put Strasbourg ahead from the penalty spot after four minutes but for Mamadou Bagayoko to level for Ajaccio after 18 minutes of play.
Mamadou Niang hit two goals in five minutes to put the hosts 3-1 in the lead and although Abdelnasser Ouadah reduced the arrears to 3-2 after 35 frantic minutes, that ended the scoring and Strasbourg secured a 3-2 win.
Bordeaux fell to a surprising 3-1 defeat at home to Sochaux despite taking the lead through a Jean-Claude Darcheville penalty after 20 minutes.
Pierre-Alain Frau grabbed a brace for the visitors either side of Mickael Isabey's strike to earn a 3-1 win at Parc Lescure.
Top-flight newcomers Metz grabbed a last-minute winner through Pape Thiaw to earn a dramatic 2-1 win at home to Montpellier after Habib Bamogo had levelled for the visitors, who had fallen behind to Stephane Borbiconi's early strike.
Last season's surprise package Nice edged a 1-0 home win over Nantes with Abdelmalek Cherrad securing all three points with his goal after 11 minutes.
Olivier Sorlin and Stephane N'Guema scored for Rennes as they enjoyed a 2-0 win at home Lens who had started the season brightly.
Match summaries:
Bastia v Guingamp
Bordeaux v Sochaux
Lille v Monaco
Lyon v Auxerre
Marseille v Le Mans
Metz v Montpellier
Nice v Nantes
Rennes v Lens
Strasbourg v Ajaccio
