Lionel Messi hit a hat-trick as Celtic’s Champions League campaign began with a 7-0 defeat to Barcelona in the Nou Camp.
The Argentina forward took less than three minutes to open the scoring and after Moussa Dembele missed a penalty at the other end, he added a second before half-time.
Neymar made it three with a free-kick shortly after the restart and after Andres Iniesta got the fourth, Messi completed his treble and Luis Suarez netted a double too.
The defeat leaves Celtic bottom of Group C with Manchester City still to play Borussia Monchengladbach on Wednesday after their match was called off because of heavy rain.
Meanwhile, in Munich, Carlo Ancelotti’s men strolled to a commanding 5-0 win over Rostov. Robert Lewandowski opened scoring in the 28th minute, Thomas Müller made it two on the stroke of half-time, Jimmy Kimmich made it five, thanks to his 53rd and 60th minute brace, before Juan Bernat made it a fiver on the stroke of full-time.
At the Parc des Princes, Arsenal fought back from a goal down to salvage a 1-1 draw with Paris Saint-Germain, despite the home side missing a plethora of chances.
Edinson Cavani headed the French side into the lead after only 42 seconds but contrived to miss several presentable opportunities to put the hosts further clear. Arsenal had few sights of goal but Alexis Sanchez levelled matters with a powerful finish as time was running out.
Both sides finished with 10 men, as Olivier Giroud and Marco Verratti were dismissed.