Long-time leaders Lille, level on points with Stade Rennes after their 2-0 win over Racing Lens on Saturday, are starting to lose some of their impetus having been beaten by Montpellier last weekend and the title run-in is set to be thrilling.
Fifth-placed Lyon remain four points behind Lille with 13 games left but could have slipped further back had Kim Kallstrom not equalised Moussa Sow's ninth minute opener for the hosts.
Sow, the league's top scorer, took his season's tally to 17 with a poacher's finish after much-hyped winger Eden Hazard's free-kick was flicked on.
Swedish midfielder Kallstrom levelled for Lyon with a fierce strike from just outside the box on 26 minutes which was too hot for goalkeeper Mickael Landreau to handle.
The stopper made amends with a top save from Jeremy Toulalan among others in the second half as Lyon, who drew 1-1 with Real Madrid in the Champions League on Tuesday, pushed hard.
Lyon, champions from 2002-2008 but whose so-so season this term has led to coach Claude Puel saying he might leave in May, lost centre-back Cris to injury in the first half.
AYEW DOUBLE
Andre Ayew earlier scored twice for champions Marseille to seal a late 2-1 win at AS Nancy with Paris Saint-Germain also strengthening their charge with a 2-1 win over Toulouse.
"We did good things, sometimes really good. We always play to win," Marseille coach Didier Deschamps told reporters ahead of games with Lille (March 6) and Rennes (March 11).
"Those games won't be crucial but they'll have a real influence."
Third-placed Marseille, who drew 0-0 at home with Manchester United on Wednesday in their Champions League last 16 first leg, slipped behind on 34 minutes when Julien Feret expertly cut in from the left to fire in at the far post from a tight angle.
Deschamps was visibly annoyed, lecturing his players on the touchline about their defending, but his mood improved as Ayew struck just before the interval when he poked in after a spot of pinball in the area following a corner.
The forward, playing because Andre-Pierre Gignac is still injured, then reached the byline three minutes from time and when his cross was blocked by the goalkeeper he slotted home.
PSG moved up to fourth after Sylvain Armand blasted in on 28 minutes and Mathieu Bodmer netted 10 minutes later when his sliding effort was deflected in off Adrian Gunino.
Franck Tabanou pulled one back for faltering Toulouse after the break to set up a nervous finish at the Parc des Princes.
