"I think the players enjoyed it more than anyone," PSG coach Laurent Blanc said. "We could have eased up at 3-0 but the players wanted to score more, and that's good."
PSG took the lead from a corner in 10th minute when goalkeeper Remy Riou saved Cavani's header and the rebound fell perfectly for Silva, giving him an easy finish from close range.
PSG doubled its lead in the 36th when Ibrahimovic sent Riou the wrong way from the spot after defender Issa Cissokho had tripped Marco Verratti just inside the penalty area. The Sweden forward has scored six penalties this season.
Brazilian winger Lucas came on for Argentina's Ezequiel Lavezzi at the start of the second half and within minutes he was involved in PSG's third goal in the 51st. His deep, floating cross from the right was headed back by Blaise Matuidi and Motta reacted quickly to slide the ball in from close range.
Ibrahimovic found himself in space on the right wing and curled in a perfect pass to give Cavani his 13th goal of the season in the 58th, and Ibrahimovic slammed the ball past Riou after Matuidi and substitute Javier Pastore combined to set him up in the 64th.
"We didn't do anything out there -- in defense, midfield or up front. They just did what they wanted. We just sat back and waited," said Nantes winger Fabrice Pancrate, who used to play for PSG. "If you don't play properly against a team like this, you get a result like that. We seemed to be terrified. I didn't recognize my teammates out there."
Cavani missed two chances to make it 6-0 when he swiped a shot wide and then hit his shot straight at Riou after going clean through in the 87th.
Earlier, left back Layvin Kurzawa put Monaco ahead in the 36th with a low shot after being set up by midfielder Geoffrey Kondogbia, sweeping the ball in after running onto Kondogbia's cross from the left.
Lucas Ocampos came off the bench to add a second with a spectacular bicycle kick in the 88th. The Argentine winger replaced Colombia forward Radamel Falcao, after he missed three chances. Falcao has only scored once in his past five games for Monaco and appears short of form.
"It's an important three points for us and it helps us get back on track," Monaco coach Claudio Ranieri said.
Lyon's goals came from striker Alexandre Lacazette and midfielder Gueida Fofana, moving the seven-time French champion up to eighth place.
