Celtic discovered Bayern Munich are still very much a European force as the Hoops suffered a 3-0 drubbing in their Champions League clash at the Allianz Arena.
The German giants had replaced Carlo Ancelotti with Jupp Heynckes following their 3-0 Group B defeat by Paris St Germain last month but any thoughts of demise were swept away as skipper Thomas Muller opened the scoring in the 17th minute before right-back Joshua Kimmich nodded in a second before half-time.
Mats Hummels headed in a third six minutes after the break and the Bundesliga champions were unfortunate their dominance was not properly reflected in the scoreline.
Celtic's 3-0 win away to Anderlecht in September means they are favourites to at least end up with a Europa League place after Christmas but they were simply outclassed by the Bundesliga side.
And after losing 5-0 to Paris St Germain in their opening fixture, it is clear they still have a way to go to compete with the big boys on the Champions League stage.
Bayern's magnificent stadium was packed with 72,000 fans, more than 4,000 of whom were Celtic supporters making themselves heard high up in the stands.
The Parkhead followers and their heroes were relieved in the sixth minute when the linesman flagged when Thiago Alcantara had the ball in the net from a Robert Lewandowski cut-back, perhaps ruling the ball had already gone behind for a goal kick, although television replays showed that was not conclusive.
A tug on the Poland striker's shirt inside the box by Mikael Lustig moments later went unpunished by Russian referee Sergei Karasev but the Parkhead defence was soon breached.
Craig Gordon did brilliantly to parry Lewandowksi's close-range header from a Kimmich cross but the unmarked Muller was on hand to fire the loose ball high into the net.
Gordon but had no chance with Bayern's second just before the half-hour mark, when Kingsley Coman beat Cristian Gamboa again down the left and crossed for Kimmich to loop a header in from 14 yards.
Moments later, Gordon saved a powerful Lewandowski drive with his left elbow and there was a feeling of doom for the Scottish champions.
Bayern's third goal was simplicity itself as defender Hummels beat Scott Brown to head in Arjen Robben's corner from the right.
It was hard going for Scotland's treble winners.
On the hour-mark Gamboa cleared a Robben header off the line, after Kimmich had fired in Bayern's 10th corner of the night, before Lewandowski guided a David Alaba cross into the net from six yards only for the offside flag to be correctly up for offside.
In the 64th minute Brendan Rodgers brought on Moussa Dembele and Tom Rogic for Leigh Griffiths and Stuart Armstrong but Bayern kept the pressure up with Gordon making saves from Robben and Lewandowski.
At the other end, as the Glasgow side rallied late on, Bayern goalkeeper Sven Ulreich beat away a Scott Sinclair drive before Hummels cleared Rogic's drive from the rebound.
Sinclair curled a shot into the net after the offside flag was up, Lustig's added-time header clipped the post with Brown ruled offside anyway but Gordon prevented a fourth when he made a brilliant save from a Lewandoswki header.