Late goals from Dries Mertens and Fernando Llorente earned Napoli a 2-0 victory as Liverpool made a slow start to their Champions League defence.

For the second season in a row, Jurgen Klopp’s side were beaten in the group stage in Naples – they lost 1-0 last October – and it was more sloppy defending which saw the game slip away from them in the final minutes.

The Reds had defended stoutly against some sustained pressure from the home side, but were unlucky to be punished when Jose Callejon skipped inside of Andy Robertson before making the most of minimal contact with the Liverpool defender and, when a VAR review failed to give the visitors a reprieve, Dries Mertens took full advantage to beat Adrian from the spot.

Meanwhile, at Stamford Bridge, Ross Barkley missed a late VAR-awarded penalty as Frank Lampard lost 1-0 to Valencia on his Champions League debut as Chelsea manager.

Chelsea had the chance to cancel out Rodrigo’s 74th-minute opener and salvage a point when the Video Assistant Referee alerted the on-field official to Daniel Wass’ handball in the area with three minutes remaining.

Barkley insisted he should take the spot-kick, snatching the ball off regular penalty taker Jorginho, but his effort cannoned off the top of the crossbar.

The late penalty controversy compounded a harsh introduction to Champions League football for Lampard, who lost Mason Mount to injury just 16 minutes and still awaits the first home victory of his tenure at Chelsea.

Chelsea host league leaders Liverpool on Renault Super Sunday – live on 4pm on Sky Sports Premier League; Kick-off 4.30pm. Valencia, meanwhile, host Leganes in La Liga on the same day (Kick-off 3pm)