Reigning champions Liverpool slipped to a 2-0 defeat at Napoli in tonight's opening Champions League group clash.

It's 108 days on from Madrid when Jurgen Klopp's side won the club's sixth European Cup trophy.

But their re-introduction to the competition didn't go as planned.

They fell behind with just eight minutes to go against last season's Serie A runners-up.

Jose Callejon won a penalty following a challenge in the box from Liverpool left-back Andrew Roberston.

Belgian forward Dries Mertens converted, although Liverpool keeper Adrian almost stopped it.

Napoli doubled their lead on 90 minutes through ex-Tottenham target-man Fernando Llorente.

The Basque striker capitalised on an error from the usually reliable Virgil van Dijk to make it 2-0.

Elsewhere in Liverpool's group, Red Bull Salzburg go top after the opening round of matches.

The Austrian side hammered Belgium's Genk 6-2 on home soil to go above Napoli on home soil.

Chelsea

It was also a night to forget for Chelsea as Frank Lampard lost on his debut as a manager in the competition he won as a player back in 2012.

Like Liverpool, the Blues fell behind in the second half against La Liga's Valencia. Spain international Rodrigo gave the visitors the lead with 16 minutes to go.

Chelsea had the chance to level from the penalty spot late on but Ross Barkley missed with his effort as Chelsea slipped to a 1-0 loss at Stamford Bridge.

They also lost Mason Mount to injury following a challenge from ex-Arsenal midfielder Francis Coquelin.

Last season's Champions League semi-finalists Ajax are currently top of that group. The Dutch champions defeated Lille 3-0 in Amsterdam.

In the night's other games, Barcelona drew 0-0 at Borussia Dortmund in Group F. Slavia Prague held Inter Milan to a 1-1 draw to leave all four sides on a point each.

In Group G, RB Leipzig won 2-1 at Benfica, while Zenit St Petersburg drew 1-1 at Lyon.

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