Former Arsenal man Serge Gnabry came back to haunt Tottenham as he scored four in Bayern Munich's 7-2 demolition in north London.
Tottenham's troubled start to the season took a massive turn downwards as they were taught the harshest of lessons by a superb Bayern side, who showed clinical finishing but were helped by some sloppy Spurs passing and complete capitulation in the final 20 minutes that will worry everyone at the club.
Heung-Min Son gave Spurs the lead after just 12 minutes after looking sharp from the first whistle, but Joshua Kimmich levelled three minutes later and Robert Lewandowski produced a brilliant turn and finish on the stroke of half time.
Former Arsenal man Gnabry then scored twice in two minutes to see the Bavarians move into a commanding lead, which Spurs then reduced to 4-2 when Harry Kane clinically dispatched a slightly harsh penalty.
Gnabry completed his hat-trick seven minutes from time though, and with Spurs reeling Lewandowski slotted in a fine sixth from a wonderful Philippe Coutinho flick to add further insult to injury.
The misery was not done just yet though, and Gnabry took the chance to add a fourth, and Bayern's seventh, late on as Spurs' collapse was complete.
It leaves Spurs with just a point after two games and in third in their group after Crvena Zvezda came from behind to beat Olympiakos 3-1 in Belgrade.
The Greek side led 1-0 when they had Yassine Benzia sent off just before the hour mark, and the Serbians took just five minutes to level - before breaking Olympiakos hearts with two goals in the last three minutes from Nemanja Milunovic and Richmond Boakye.
Spurs next face back-to-back games against Red Star in what could be a crucial couple of games in their qualification hopes.