Monaco laid the gauntlet down to Paris Saint-Germain by coming from behind to beat Toulouse 3-1 at Stade Louis II ahead of the Ligue 1 champions' trip to Nice.
Jemerson's defensive lapse put the opener on a plate for Ola Toivonen in the first minute of the second half, but Kamil Glik quickly restored parity before Kylian Mbappe and Thomas Lemar sealed victory, helping the hosts respond to their 5-0 Coupe de France thrashing to PSG in midweek.
Monaco restored their three-point lead over PSG with both teams having played 34 matches, piling the pressure on Unai Emery's champions ahead of their trip on Sunday to Allianz Riviera, where Nice are unbeaten domestically in 14 months.
Radamel Falcao endured a frustrating outing in front of goal, seeing a seventh-minute effort scrambled off the line by Toulouse goalkeeper Alban Lafont.
Neither side could find a breakthrough before the break, but Toulouse were in front less than a minute into the second half as Jemerson made a hash of trying to clear a cross from the left and Toivonen pounced to score.
Monaco were behind for all of three minutes as Glik turned in Joao Moutinho's free-kick and only a stunning stop from Lafont prevented Falcao from putting Monaco ahead.
Lafont undid his own good work two minutes later, however, clearing straight to Bernardo Silva who put the ball into the path of Mbappe and the teen sensation beat the goalkeeper at his near post with an arrowing effort.
Toulouse retained a threat on the counter but the game was put to bed when Moutinho brilliantly chested Silva's ball to Nabil Dirar and he picked out Lemar at the back post for a simple tap-in.