In the most stunning result of the final night of first-round Champions' League matches, the five-time champions of Europe - just four minutes away from the next stage of the event - had the rug pulled out from underneath them by the Turks in losing 3-2. Hakan Sukur headed home Pembe Ergun's cross after the Milan defence failed to clear, and Daval Umit then converted a penalty.
The Italian newspapers have labelled the defeat a disaster, with Zaccheroni coming under fire in all of them. The Corriere dello Sport wrote: "Zaccheroni, at this moment in time, is hanging on to his job by a thread."
Tuttosport blasted the late collapse, writing: "Milan madness, out of everything".
Milan, who surrendered their Uefa Cup place to Galatasaray in the process, now have only the Serie A title and the Coppa Italia to play for.
"This is the worst defeat of my career," said Zaccheroni. "I cannot begin to explain how it could have happened. We had the right attitude; we were brave and really chased the win. We were well prepared and had spent a lot of time studying our opposition beforehand. We played the entire game at our own speed and really dictated the pace, especially up front."
The Milan captain, Paolo Maldini, was distraught. "Coming last in our Champions' League group simply isn't good enough," he said. "That is not the kind of result you expect from a team like Milan. We let Galatasaray back into the game, because we didn't play the ball well. If we had been calmer we probably would have won, just as Chelsea did in Istanbul. Instead, it's finished like this."
The Milan vice-president, Adriano Galliani, ruled out a change of coach - but his boss, the club's president Silvio Berlusconi, was tight-lipped about the future of Zaccheroni. "I don't want to talk about last night," Berlusconi said. "My heart is in pain."
Press reports yesterday said that Galliani and Berlusconi had spoken at length after Wednesday's defeat. However, Galliani, who runs the day- to-day business of the club, said of Zaccheroni's position: "It is not up for discussion."
Galliani was shocked by his side's exit. "It is not possible to have a chance to remain in the Champions' League and then suddenly to end up bottom of the group, it's just not possible. In the second half we played really badly, we just weren't the real Milan," he commented.
Galliani said Milan now had to concentrate on qualifying for next season's Champions' League. "We have got to get back into Europe as soon as possible by finishing in the top four in the league. We can do it because we have a team which won the league just three or four months ago," he said.
Galliani also paid tribute to Chelsea for their 2-0 victory over Hertha Berlin which left them top of Group H. "Chelsea played an extraordinary game and were a real tribute to the sport," he said.
Arrigo Sacchi, the former Milan and Italy coach, now a television pundit, said: "Everyone says the favourites for the Champions' League title are Barcelona, Manchester United and Lazio, but I would include Chelsea in that list."
On Wednesday Zaccheroni said: "Having a place in the Champions' League in your hands one minute and then nothing at all the next minute is very difficult to accept. I saw some of the players in the dressing-room and they really had their heads down." He said he had not yet considered making major changes to his squad.
"I haven't thought about that possibility simply because I was hoping to go forward in the Champions' League," he said. "I don't like to look for excuses straight after a game but probably our biggest mistake was that we didn't have enough possession of the ball."
Zaccheroni suggested that the pressure of the occasion may have caught up with his side in those final decisive moments. "Possibly in those final minutes we paid for the amount of nervous energy we expanded," he said. "We have to get better, we have to do what we did last season and improve the quality of our play noticeably."
Jubilant Turks took the streets sounding klaxons and waving Galatasaray red and yellow flags from car windows. "We deserved the Champions' League, but we ought to be grateful for having put a giant like Milan under our belts and moving on to the Uefa Cup," said the club's coach, Fatih Terim.