Liverpool’s defence of the Champions League trophy got off to a disappointing start as the Reds conceded two late goals to lose 2-0 in their Group E opener at Napoli.
Dries Mertens broke the deadlock when he fired home a penalty eight minutes from time after Andy Robertson was harshly adjudged to have brought down Jose Callejon.
And former Tottenham striker, Fernando Llorente, who spoke of wanting revenge for losing the Champions League final back in June, came off the bench to seal the points following a rare mistake from Virgil van Dijk.
The Merseysiders had their chances in a keenly contested affair, but Roberto Firmino headed wide and Mo Salah saw a rasping drive well saved by Alex Meret.
Jurgen Klopp’s side lost 1-0 in the San Paolo at this stage last season and they found the Partenopei to be tough opposition once again, with Adrian producing a sensational second-half save to deny Mertens when the game was still scoreless.
The result means Napoli take second place behind Salzburg, who lead the pool after Matchday One courtesy of their thumping 6-2 victory over Genk.
Liverpool will now look to bounce back in Sunday’s clash at Chelsea as the Merseysiders bid to extend their perfect start to their league campaign.
Ross Barkley missed a late penalty as Chelsea opened their Champions League campaign by losing at home to Valencia.
Willian had an early shot saved by Jasper Cillessen before Chelsea lost midfielder Mason Mount to injury.
Valencia, who lost 5-2 at Barcelona on Saturday, broke the deadlock as Rodrigo volleyed in Daniel Parejo’s free-kick.
And that proved to be the winner as substitute Barkley fired over after the video assistant referee awarded a spot-kick for handball by Daniel Wass.
In Germany, Marc-Andre ter Stegen saved Marco Reus’ penalty as Barcelona held Borussia Dortmund to a goalless draw in their Champions League opener.
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.
Last year semi-finalist Ajax Amsterdam gave a powerful reminder of their Champions League potential with a resounding 3-0 win over Lille in Amsterdam on Tuesday at the start of the group phase.
In other results, Inter Milan were held by Slavia Prague 1-1, RB Salzburg battered Genk 6-2, RB Leipzig stunned Benfica 2-1 and Lyon shared the spoils 1-1 with Zenit in France.