The Champions League started yet another iteration with 32 teams vying for Europe's top prize. While some like Barcelona and Bayern had an easy day at the office, PSG and Arsenal both had a man sent off in a pulsating encounter at the Parc des Princes.

Spanish champions Barcelona tore into the hapless Celtic defense, handing them a 7-0 defeat at the Camp Nou. Lionel Messi was at his imperious best, netting one of the easier hat-tricks of his career. Luis Suarez grabbed a brace while Andres Iniesta and Neymar got a goal each.

Only seven of the evening's eight matches were played, with Manchester City's match with Borussia Monchengladbach also called off due to poor weather conditions.

PSG and Arsenal involved in classic

The marquee fixture of the evening lived up to its billing as both teams played out a thriller, one soured by the late sending-offs of Olivier Giroud and Marco Veratti.

The match started with a bang as the home side, Paris Saint-Germain, were ahead within 44 seconds - Serge Aurier surged ahead from right-back to cross it to Edinson Cavani, who made no mistake in heading the ball past David Ospina, who was standing in for the injured Petr Cech.

Cavani and PSG had several chances to put this game to bed but kept missing routine chances as Arsenal clawed their way back into the game. Alex Iwobi's shot was parried into the path of Alexis Sanchez, who was unerring in his finish.

The home team's grief at having conceded only increased when Giroud and Veratti were involved in an off-the-ball confrontation. They each received second yellows and will miss their club's next Champions League fixtures through suspension.

Messi hat-trick fuels Barcelona's Scottish party

Barcelona, still smarting from their weekend defeat at the hands of Alaves, handed a spectacular 7-0 shellacking to Celtic, who were handed their worst European defeat. Lionel Messi provisionally crossed Cristiano Ronaldo as the holder of the most Champions League hat-tricks. Messi now has six hat-tricks in this competition.

It was the 5-time Ballon d'Or winner who opened the floodgates, netting two goals by half-time. The opener came in the third minute. Barca took their corner short, and Messi, who had space on the left, thumped the ball from a tight angle.

The Scottish giants had the chance to equalise from the penalty spot but Marc-Andre ter Stegen went the right way to save Moussa Dembele's effort.

Barca woke up with a vengeance and Messi scored in the 28th minute, poking the ball home from close range after Neymar set the goal up through some excellent work on the left flank. The Brazilian scored in the second half with a free kick from 25 yards out.

Andres Iniesta, who had come on as a substitute in the second half hammered a delightful volley to make it four.

Minutes later, Messi got his treble from a Luis Suarez cut-back from close range. Suarez got on the scoresheet with a brilliant goal, chesting the ball and finishing it with his left foot. The Uruguayan grabbed the seventh with a slide from three-yards out, assisted by Messi to complete the rout against Brendan Rogers' side, whose defense was shambolic throughout.

Bayern thrash halpless Rostov

FC Rostov had a Champions League debut to forget, as the German champions put them to the sword, putting five goals past the Russian club.

Aleksandru Gatcan conceded a penalty in the 28th minute when he tugged Bayern striker Robert Lewandowski's shirt in Rostov's penalty box. The Polish striker then stepped up to give Munich the lead. Thomas Muller made it two on the stroke of half-time when he volleyed David Alaba's cross home.

Right-back Joshua Kimmich bagged Bayern's third and fourth goals - the third, a tap-in from close range while the fourth was a header from a Juan Bernat cross in the 60th minute.

Provider became goal-scorer in the 90th minute when Bernat turned in a pass from Franck Ribery to score Bayern's fifth goal.

Atletico's Saul scores another screamer

It was always going to be a cagey affair and the Atletico Madrid-PSV Eindhoven match lived to its pre-match billing. Saul Niguez, one of Spain's brightest young attacking midfielders, also lived up to his hype, scoring yet another spectacular goal. Last year, Niguez had scored one of the season's best goals through a mazy solo effort against Bayern Munich in the semi-finals.

The transfer ban and a hefty fine to go along with it only seems to have galvanised last year's finalists, who delivered a staunch 'away' display. Gabi's well directed corner found Gabi in the box, whose shot bounced off the PSV defense. Niguez, who was at the edge of the box found the left corner of the net through a terrific karate kick to put his side in the lead. Atletico held on to get to their second consecutive win in all competitions.

Manchester rains postpone City-Gladbach tie

Heavy thunderstorms in Manchester washed out the Manchester City-Borussia Monchengladbach match at the Etihad stadium. The decision was made 15 minutes before the kick-off time. It was also announced that the fixture will be played a day later.

The rains had eased out but the officials deemed the conditions unsuitable and dangerous for play after multiple inspections after concerns grew over the many puddles that had formed around the playing area.

The Results

  • Basel 1 (Renato Steffen) draw with Ludogorets Razgrad 1 (Jonathan Cafu)
  • Paris Saint Germain 1 (Edinson Cavani) drew with Arsenal (Alexis Sanchez)
  • Benfica 1 (Franco Cervi) drew with Besiktas 1 (Anderson Talisca)
  • Dynamo Kyiv 1 (Denis Garmash) lost to Napoli 2 (Arkadiusz Milik X 2)
  • Barcelona 7 (Lionel Messi - 3, Luis Suarez - 2, Andres Iniesta, Neymar) beat Celtic 0
  • Bayern Munich 5 (Robert Lewandowski penalty, Thomas Muller, Joshua Kimmich X 2, Juan Bernat) beat Rostov FC 0
  • PSV Eindoven 0 lose to Atletico Madrid 1 (Saul Niguez)
  • Manchester City vs Borussia Monchengladbach: Postponed