Big-spending Paris St Germain avoided a defeat that could have derailed their Champions League campaign when Angel Di Maria curled in a delightful stoppage-time equaliser to rescue a 2-2 draw at home to Napoli on Wednesday.

Napoli went ahead in the Group C game with a Lorenzo Insigne goal in the 29th minute before PSG, who have won their opening 10 games in Ligue 1, equalised when Mario Rui put through his own goal in the 61st minute.

An opportunist goal by Dries Mertens put Napoli back in front in the 77th minute but they were denied a shock win when Di Maria collected the ball on the edge of the area and curled a stunning effort past David Ospina in the third minute of stoppage time.

The drew left Napoli with five points from three games and PSG on four with Liverpool top with six. Defeat for the French side would have left them three points adrift of the leading pair.

It was a cruel finale for Ospina, who had kept PSG at bay with several outstanding saves.

Napoli coach Carlo Ancelotti was returning to the Parc des Princes for the first time since leading Bayern Munich to a 3-0 defeat there last September. He was sacked by the Germans the following day.

PSG created a flurry of early chances, the best falling to Edinson Cavani when he was sent clear of the Napoli defence only for Ospina to block the Uruguayan's effort.

Napoli's first dangerous foray upfield nearly ended in a goal as Mertens thumped the ball against the crossbar from an inviting Mario Rui cross.

In the next attack, Jose Callejon curled a ball behind the PSG defence and into the path of Insigne, who gently flicked his shot over Alphonse Areola.

Ospina then made another one-on-one save, this time foiling Kylian Mbappe.

The Colombian was also busy after the break and he blocked a low Neymar shot and then tipped a Thomas Meunier header over the bar but he was left powerless when Mario Rui slid in and diverted Meunier's low cross into the net.

Mertens put Napoli back in front, reacting quickly to fire past Areola after Fabian Ruiz's shot hit PSG captain Marquinhos and landed at his feet.

The visitors were heading for top spot until Di Maria's goal threw the group wide open and provided a fitting end to an enthralling match.