Edinson Cavani, Zlatan Ibrahimovic, Layvin Kurzawa and Jean-Kevin Augustin scored as Laurent Blanc’s side made it nine consecutive league wins.
It was PSG's first home match since the attacks on Paris by Islamic State members on Nov. 13 that killed 130 and injured at least 350.
"To be autumn champions is a good thing," coach Blanc told reporters, "in so much as it confirms that we’re taking an enormous amount of points.
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"It’s no guarantee of ending the season as champions. What interests us is to be champions (at the end)."
Cavani responded to Blanc's recent calls for him to find the net more regularly by opening the scoring in the 20th minute, meeting Angel Di Maria's audacious cross with a measured volley.
The home side lacked the focus and intensity that has characterised some of their recent victories but never looked like losing their lead.
PSG doubled their advantage in the 58th minute when Ibrahimovic scored from the penalty spot after Chris Mavinga brought Lucas Moura down.
Kurzawa made it 3-0 with a superb volley from outside the area before substitute Augustin added a fourth in the 84th minute, four minutes after coming on as a substitute, when his long-range shot was misjudged by goalkeeper Paul Bernardoni.
Troyes responded when Thomas Ayasse curled an effort over Kevin Trapp in stoppage time.
Angers are up to second place after a 2-0 victory over Lille, for whom Frederic Antonetti was making his debut in the dugout.
Gilles Sunu netted after 20 minutes before IsmaelTraore added a second goal five minutes later to end a four-match run without a victory for Angers.
Third from bottom Lille have now gone six games without a win.
Stade Rennes drew 2-2 at Stade de Reims who had coach Olivier Guegan sent to the stands for protesting against a 64th-minute red card given to Jaba Kankava.
The point ended Reims' six-game losing streak but theyremained 15th on 16 points, six behind Rennes who are seventh.
Ajaccio's winning run came to an end with a 1-1draw at home to Lorient, league top scorer Benjamin Moukandjo notching his 11th goal of the season for the visitors.
Toulouse beat 10-man Nice 2-0 while Nantes and Bastia played out a goalless draw.
(Writing by Ed Dove; Editing by Tony Jimenez)
