A 2-0 home win over Angers on Wednesday was PSG's fifth victory on the bounce in the league.
The French champions appeared to struggle early on with new coach Unai Emery's methods, but a 2-0 home win over Angers on Wednesday was their fifth victory on the bounce in the league and in the Uruguayan Cavani they have one of Europe's red-hot predators.
Cavani bagged his 100th goal for PSG in the Angers triumph -- also making it 19 goals in 18 matches this season -- and mercurial playmaker Hatem Ben Arfa is also back in favour with Emery after a slow start to his career in the French capital.
Emery said he wanted even more from Cavani, 29, who took over as PSG's leading man in the summer after Zlatan Ibrahimovic moved to Manchester United.
"He's working to do the best he can and to help the team. I'm waiting for Cavani to make this the best season of his career, that's what I want," the Spaniard Emery said.
PSG will be expected to win at Montpellier, who sit below mid-table and are on a poor run of form, and victory would see the Parisians overhaul Nice at the top.
However, Nice can reclaim top spot on Sunday when they host Toulouse.
The surprise leaders, who have lost just once this season, travel to PSG on December 11 for what is shaping up to be an early Christmas cracker.
First they need to see off Toulouse and they may need again to do it without Italian striker Mario Balotelli, who has a calf problem. He missed Wednesday's 1-0 win at Guingamp.
Nice boss Lucien Favre is refusing to contemplate the PSG showdown just yet and warned his players that Toulouse, eighth in Ligue 1, would be a stubborn test.
"They are tough opponents," he said after the hard-fought Guingamp win.
"May I remind you they are the only side to have beaten both Paris SG and Monaco, so that will be a big match."
PSG romped to the title last season, but this term it is looking very much like a three-horse race.
Going into this weekend's action, after 15 games, Nice top the pile with 36 points, followed closely by PSG (35 points) and Monaco (33). Lyon are fourth on 25 points.
Monaco, who dumped Tottenham Hotspur out of the Champions League last week, followed that up on Tuesday with a disappointing 1-1 draw at lowly Dijon.
Coach Leonardo Jardim saw his side concede an 87th-minute equaliser and Monaco can ill-afford lapses like that home to Bastia on Saturday if they are to keep up the pressure on the top two.
"This draw is a bad performance," Jardim fumed.
"We opened the scoring early (through Argentine forward Guido Carrillo on 17 minutes), but then we lost control of the match and we made a lot of unusual mistakes.
"Dijon took advantage of that, winning duels, and they deserved the draw."
Dijon, who are 15th, kick off the latest round of games in France on Friday when they go to Caen.
Like the visitors, Caen are fighting for their lives and are down in 18th of the 20 teams.
Fixtures (all times GMT):
Caen v Dijon (1945)
Montpellier v Paris Saint-Germain (1600), Bordeaux v Lille, Angers v Lorient, Monaco v Bastia, Guingamp v Nantes, Metz v Lyon (all 1900)
Rennes v Saint-Etienne (1400), Marseille v Nancy (1600), Nice v Toulouse (1945)