The big-spending capital club returned to the top of the table thanks to their convincing triumph at the Parc des Princes, which came seven days after a surprise 2-1 reverse against Rennes.
The rout capped a good few days for PSG,who secured their place in the last 16 of the Champions League with a 2-0 victory over Dynamo Kiev in Ukraine on Wednesday.
"I'm very happy after an excellent week for us," Ancelotti said. "After qualifying for the last 16 of the Champions League, we are back to winning ways at home.
"Obviously we need to keep working. The squad's response after the Rennes loss was very good.
"The next match against St Etienne (on Tuesday) is also very important because we want to give it the absolute maximum in the Coupe de la Ligue.
"It will be very difficult because St Etienne are a good team, who beat us here at the Parc (1-2), but we want to win."
Maxwell gave the hosts the lead midway through the first half before Blaise Matuidi doubled their advantage with just over 20 minutes left.
It was then left to star striker Zlatan Ibrahimovic to bag a brace and with it his 200th competitive league goal.
Defender Sylvain Armand said: "After the European qualification in Kiev, the idea was to get back to winning ways after three games without a win.
"It wasn't easy, but we did it, despite some nervy moments. Playing every three or four days is not easy, but winning 4-0 is obviously a positive thing.
"After Rennes, we told ourselves we needed a big week to get back on track, so obviously we're very happy with the win. Now we have to recover well for the next challenge against St Etienne on Tuesday."