Naples-Sana
Liverpool started the defense of the Champions League title with a 2-0 defeat away to Napoli at the San Paolo Stadium.
Dries Mertens scored from the penalty spot eight minutes from time after Andy Robertson blocked Jose Cajon and substitute Fernando Llorente added a second in stoppage time to confirm the hosts' superiority.
In another Group E match, Salzburg made a spectacular start and swept away Genk 6-2.