Paris (AFP) – Barcelona’s lethal MSN — Lionel Messi, Luis Suarez and Neymar — dissected Celtic 7-0 while a deluge washed out Pep Guardiola’s eagerly awaited first Champions League game in charge of Manchester City on Tuesday.

There was no rain but there was a flood of goals at the Camp Nou, where a sparkling Messi hat-trick with four assists and a goal from Neymar, Andres Iniesta and a Suarez brace humiliated Celtic.

Celtic will have to shrug off this worst ever European defeat and Brendan Rodgers’s largest loss as a manager as their next Group C outing is at home to City.

After the weekend derby defeat of Manchester United, City had Borussia Moenchengladbach firmly in their sights but the fixture was called off just 20 minutes before kick-off with the Etihad Stadium hit by heavy rain.

The match will now be played on Wednesday.

The first goal of the 2016/2017 Champions League group stages came after a mere 42 seconds from the head of Paris Saint Germain striker Edinson Cavani at the Parc des Princes against Arsenal.

The strike was PSG’s quickest in the Champions League, but the French champions, and Cavani in particular, were guilty of failing to convert a succession of golden opportunities.

The worst possible start for Arsenal hinted at a potential lopsided affair but the Gunners got out of jail with Alexis Sanchez’s leveller inside the final quarter of an hour.

Both sides ended a man down after Olivier Giroud and Marco Verratti were sent off at the death.

Arsenal’s night got better with news that Group A’s other game between Basel and Ludogorets also ended 1-1.

Guardiola’s old side Bayern Munich, under new boss Carlo Ancelotti, ran riot over Russian side Rostov 5-0.

Joshua Kimmich grabbed a second-half double, with Robert Lewandowski scoring from the penalty spot, birthday boy Thomas Mueller and Spanish defender Juan Bernat giving Bayern early custody of Group D.

But only on goal difference as Atletico Madrid won 1-0 at PSV Eindhoven, Saul Niguez doing the damage with a sizzling scissor-style volley just before the break.

Napoli meanwhile may have lost their prolific goal-scoring machine Gonzalo Higuain after the Argentine jumped ship to Serie A rivals Juventus, but his replacement, Arkadiusz Milik, earned them a 2-1 win at Dynamo Kiev.

Denys Garmash put Kiev in front but Milik’s pair of opportunistic headers earned Napoli a key away success against a side that ended with 10-men.

Napoli sit top of Group B after Benfica were undone by one of their own players.

Franco Cervi sent the Portuguese side into an early lead against Besiktas but the Turkish visitors got an injury time equaliser courtesy of Talisca, loaned to Besiktas by Benfica last month.

Barca meanwhile could face fresh sanctions from UEFA after thousands of separatist Catalan flags were again flown at the Camp Nou.

The Spanish champions were fined 150,000 euros ($170,000) by UEFA because of the flags during last season’s competition.