Alex rescued Paris Saint-Germain from a second defeat in three days as the Brazilian defender's late goal earned a 1-1 draw at Guingamp in Ligue 1 on Saturday.
The leaders were knocked out of the Coupe de France by Montpellier in midweek and another loss looked to be on the cards when they fell behind to a Mustapha Yatabare strike in the 84th minute.
However, former Chelsea man Alex struck four minutes later to secure a result which takes PSG six points clear of Monaco, who are in action at home to Marseille on Sunday.
Montpellier followed up their shock cup win over PSG with a 3-1 win over Nice that moves them six points clear of the bottom three.
Goals from M'Baye Niang, Vitorino Hilton and Souleymane Camara proved more than sufficient to see off Nice, who replied through Alexy Bosetti.
Rock-bottom Ajaccio and second-last Sochaux shared the points in a 1-1 draw at Stade Francois-Coty thanks to Vincent Nogueira's stoppage-time equaliser.
Benjamin Andre got Ajaccio off to the perfect start in the eighth minute when he beat goalkeeper Simon Pouplin at the far post, and the Corsican side looked to have claimed their second win of the season until Nogueira levelled in the 93rd minute.
The result keeps Ajaccio two points behind Sochaux, who are in turn nine points from safety.
Third-bottom Valenciennes claimed a point against Lorient in a 1-1 draw at the Stade du Hainaut.
Saliou Ciss' 39th-minute own goal had given Lorient the lead but Gregory Pujol netted the equaliser for the home side shortly after the break to claim a vital point.
Nantes and Reims played out a goalless stalemate that maintains both teams' unlikely assault on the top six, while the fixture between Toulouse and Bastia was postponed after heavy rain caused a high risk of flooding around the Stadium Municipal de Toulouse.