Cavani and Neymar were both assisted by their 19-year-old teammate, with Mbappe putting on an excellent display of speed, strength and dribbling throughout the game. The France striker sealed PSG's win with a goal in added time.
Marquinhos was also on the scoresheet for PSG after Marko Gobeljic cut Belgrade's deficit in the second half. Despite just one victory in its first four games, PSG advanced as Group C winner, two points ahead of last season's runner-up Liverpool, which qualified for the last 16 with a 1-0 win over third-place Napoli.
"We knew this would be a very tough group that would be up for grabs right to the end," Marquinhos said. "We've managed to finish top, which is very good, and it gives us an advantage for the next round."
PSG coach Thomas Tuchel fielded the same players who started against Liverpool in a 2-1 victory two weeks ago. Knowing that a win would seal its spot in the next stage, PSG immediately took control of the ball and forced Red Star players to defend close to Milan Borjan's goal.
Mbappe created the visitors' first opportunity with a surge down the left, easily getting past Belgrade captain Filip Stojkovic to cross the ball for Cavani, who scored in the ninth minute with a simple tap in.
With top-ranked tennis player Novak Djokovic watching from the stands, the hosts played more aggressively after conceding their first goal at home this season in the Champions League but PSG continued to dominate with better discipline and team play.
Neymar made it 2-0 five minutes before the interval with a beautiful solo goal. After latching onto a pass from Mbappe on a counterattack, the Brazil star cut into the area from the left, got past two defenders, feinted a shot in the run-in and chipped the ball into the net.
The hosts were more inspired in the second half and threatened with a series of well-built attacking moves. Red Star pulled one back in the 56th, following a good combination on the left side when Milan Rodic crossed the ball for Marko Gobeljic, who beat Gianluigi Buffon with a fine volley at the near post.
The goal ensured some suspense until Marquinhos made it 3-1 with a header from Angel Di Maria's free kick in the 74th. Mbappe wrapped up the win in added time with a powerful strike through Borjan's legs.
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