Paris Saint-Germain opened up an eight-point lead at the top of Ligue 1 on Wednesday after a 4-1 victory at Monaco.
Kylian Mbappe scored against his former side when he combined with Angel Di Maria after 14 minutes.
Neymar struck from a penalty on the stroke of half-time, slotting home in stoppage time after Kamil Glik fouled Layvin Kurzawa.
Pablo Sarabia's 72nd-minute volley wrapped up the points as PSG ran out comprehensive winners at Stade Louis II.
Tiemoue Bakayoko scored a consolation for the hosts with three minutes remaining, but Mbappe completed his brace during stoppage time off an assist from Neymar.
PSG's attack was in full flight against one of their traditional top-flight rivals, and with 12 shots on target, the scoreline could have been worse for Monaco.
Mbappe had ice in his veins as he made sure of his opener, and the writing was on the wall for the home team.
The champions dominated the early stages, and it was a surprise it was still only 1-0 as the interval approached.
However, the visitors doubled the advantage when Neymar struck from the penalty spot, and repeat of Sunday's 3-3 draw between the two teams in the capital appeared unlikely at half-time.
Monaco struggled to create as PSG found an economical rhythm, and Marco Verratti's world-class pass was tucked away by Sarabia with 18 minutes left on the clock.
Robert Moreno's team could not repeat their recent display at PSG, but Bakayoko steered home Adrien Silva's free-kick for a late goal.
Mbappe will feel he should have scored a hat-trick after opportunities in the final moments. The 21-year-old combined with Neymar to make it 4-1 in the first minute of stoppage time, but should have completed a treble seconds after.
Monaco goalkeeper Benjamin Lecomte frustrated Mbappe, with the striker attempting to nudge the ball past him.
PSG are now clear at the top of the division. Marseille remain in second, but the leaders extend their advantage over Les Olympiens.
PSG play Lorient of Ligue 2 on Sunday in the Coupe de France, while Monaco travel to Championnat National 2 side St-Pryve St-Hilaire on Monday in the same competition.