Defending champions Liverpool have lost the opening match of their new Champions League campaign.
The Reds went down 2-0 to Napoli on Tuesday night as Dries Mertens and Fernando Llorente scored late goals for the Italian side.
Elsewhere, Marc-Andre ter Stegen saved a penalty as Barcelona held Borussia Dortmund to a goalless draw.
Chelsea's return to the Champions League saw Valencia claim a 1-0 victory at Stamford Bridge.

Pakistan survive Dutch scare in T20 World Cup opener
Arqoub Al Sadeera Race to conclude 10th Al Salam Cycling Championship
Open Masters Games Abu Dhabi welcomes over 25,000 athletes
Ekaterina Alexandrova rallies to advance to Abu Dhabi finals
Sooryavanshi's record 175 guides India to Under-19 World Cup glory
