Victor Osimhen's first-half penalty gave Galatasaray a 1-0 win over Liverpool on a disastrous night for Arne Slot's side, who suffered back-to-back losses for the second time under the Dutchman.
It was an evening which saw more defensive errors at the back for Liverpool, multiple big chances wasted too - plus a doubly injury blow to goalkeeper Alisson and striker Hugo Ekitike.
Arne Slot made a surprise selection with Mohamed Salah and Alexander Isak both named on the bench - with Jeremie Frimpong starting at right wing - but what did not change was Liverpool's vulnerability at the back.
They were given a huge warning in the opening minutes as Baris Aper Yilmaz was played through on goal - with too much power and pace for right-back Dominik Szoboszlai. The forward forced a good save from Alisson Becker - before Liverpool missed a huge chance of their own.
Ekitike was played through on goal but rolled his foot on the ball instead of shooting, in an attempt to round goalkeeper Ugurcan Cakir. The Galatasaray shot stopped read it, before Ismail Jakobs cleared the rebound off the line from Cody Gakpo.
And 23 seconds later, Liverpool were made to pay. Yilmaz had the better of Szoboszlai again on the break and when the winger cut inside, Szoboszlai caught him with a flailing arm on the face. Referee Clement Turpin spotted it, allowing Osimhen to fire the spot kick down the middle against Alisson.
Liverpool's response was better. Florian Wirtz forced a good save from Cakir while Milos Kerkez and Ibrahima Konate missed big close range chances from separate corners.
A wasteful Liverpool missed a grand total of 1.19 xG in the first half and it continued after the break, with Ekitike's close-range flick being kept out instinctively by Cakir.
Then came a big moment as Ibrahima Konate made another error with a poor square pass to Ryan Gravenberch, who had a tough night. Osimhen latched onto the ball and while Alisson kept it out, it came at a cost as the Liverpool goalkeeper immediately limped off injured.
Liverpool brought on Salah and Isak, with the latter firing straight at Cakir almost straight away from a good area. The Reds' momentum was stifled further as Ekitike stretched for the ball then pulled up, meaning he came off for Alexis Mac Allister.
Conor Bradley put a header wide of goal - before the Reds thought they had a way back in when Konate went down under Wilfried Singo's challenge and referee Turpin pointed to the spot. But replays showed Singo clearly got the ball - and VAR correctly stepped in to overturn the spot kick.
There would be no late drama this time for Slot's side, who have now hit a real bump in the road.
More to follow.