Champions League holders Paris Saint-Germain stunned Barcelona with a 90th-minute Goncalo Ramos winner to claim a 2-1 away victory in the league stage on Wednesday.

Ferran Torres sent Hansi Flick's Barcelona ahead with a cool finish but Senny Mayulu fired a depleted PSG level before half-time.

It was an even and thoroughly entertaining bout between two of the competition's favourites at the Olympic stadium which was eventually settled by Ramos' late strike, as PSG exploited Barca's high defensive line.

"After scoring the (first) goal we got a confidence boost and in the second half we were better," Luis Enrique told reporters. "I'm happy, because it's an important victory and playing against Barcelona is always difficult."

Luis Enrique, who won the treble coaching Barcelona in 2015, was lacking several key players and his team held on at times but eventually got the better of last season's semi-finalists.

"If you let in a goal in the last minute and you lose at home, you're going to be disappointed," Barcelona midfielder Frenkie de Jong said.

"There's a long way to go in the Champions League. It was a good game to test where we are. We have to improve," he added. "We know that and we will do it." (AFP)