Dries Mertens’ penalty and a late Fernando Llorente goal condemned Liverpool to defeat in their Group E Champions League opener against SSC Napoli.
Belgian forward Mertens scored from the penalty spot after Liverpool defender Andy Robertson was judged to have fouled Jose Callejon.
Former Tottenham forward Llorente then capitalised on a mistake from Virgil van Dijk in stoppage-time to roll the ball past Liverpool keeper Adrian.
This defeat has thus made Jurgen Klopp’s side the first defending Champions of the competition to lose the opening game of the following campaign since AC Milan in 1994.
In London, Ross Barkley missed a late penalty to deny Chelsea a point, as the Blues UEFA Champions League campaign under Frank Lampard began with a 1-0 loss to Valencia in Group H.
Valencia’s off-the-field issues have overshadowed their on-field exploits since Marcelino’s sacking last week, but Albert Celades’ side bounced back from their 5-2 defeat to Barcelona with a resilient performance at Stamford Bridge.
With Jasper Cillessen in fine form and Mason Mount’s injury having compounded Chelsea’s frustrations, the Blues’ frailties were exposed once more when Rodrigo Moreno prodded in Dani Parejo’s free-kick with16 minutes remaining.
VAR came to Chelsea’s rescue when the referee decided to award the hosts a spot-kick for a Daniel Wass handball, but substitute Barkley – who overruled Willian to take the penalty – struck the bar.
In Germany, Marc-Andre ter Stegen saved Marco Reus’ penalty as Barcelona held Borussia Dortmund to a goalless draw.
The Germany international also denied Reus with a smart double save as Dortmund dominated the second half.
Julian Brandt did beat Ter Stegen late on but his effort hit the bar.
Barcelona gave a Champions League debut to 16-year-old Ansu Fati but created little, despite Lionel Messi’s first appearance of the season off the bench.