In a game that many saw as a chance for AC Milan to showcase the talents of their new acquisitions, Bologna came to the San Siro and played enough football to walk off the pitch with three points.
For the visitors, Terzi was impressive at the back, along with former Milan man Antolini in goal. Though their midfield was outplayed for most of the game Amoroso played well, setting up the first goal, and Valiani scored the winner.
The game had a relatively tame opening, until Bologna struck with some good work down the right side, creating an opening for Amoroso in the box, who appeared to overplay his touch, which, in turn, went perfectly to the oncoming Di Vaio who opened the scoring in the 19th minute.
Milan looked a little surprised, and to a certain extent, they probably were. They were enjoying the bulk of possession and were not seriously threatened before this moment.
Inzaghi was having the beginnings of a game he would rather forget at the other end, as Ronaldinho put him in a couple of times, including a deft chip, which had him one-on-one to beat Antolini, but he hit his shot into the side netting.
Flamini made a long-range attempt in the 39th, but it was easily saved by Antolini and the former Arsenal man did not really figure in the match after this. He will have to improve or will be surplus to requirements when Kaka and Gatusso return.
But the equaliser was to come before the break, with Ronaldinho the provider for Ambrosini to powerfully head home in the 41st minute.
After the break it looked as though Milan were going to score several goals, rather than none, as Ronaldinho did everything but pick the ball up and place it on the spot for his strikers.
Inzaghi was perhaps most guilty when he hit a free header, set up by Ronaldinho again, straight at the keeper, in perhaps the easiest chance of the match.
Shevchenko had been introduced as a striking partner for Inzaghi at the break, as Milan went to a 4-4-2 formation and he also could have benefited from the Brazilians generous passing, instead his far-post effort was well saved by the legs of Antolini.
It was the Ronnie show for the first 20 minutes of the second half, as the Brazilian attempted to manufacture the victory for his teammates who just could not convert the chances.
The referee did play a telling part in the result though, as he waved away a penalty shout for a handball by a Bologna defender, and he then pulled up Shevchenko for a push that didn't happen when Ronaldinho was clearly in a position to put Milan ahead.
It all went horribly wrong for Milan in the 79th minute when a fortunate rebound ended up bouncing nicely for Bologna's Valiani to half-volley a spectacular winner. It was a peach of a goal really and a real kick in the teeth for Milan who didn't manage to recover.
In the closing minutes, the camera showed Ancelotti lighting up a cigarette as he watched his team lose a match that they could have, and should have, easily won. Maybe after this result, they will all be having a cigarette in the changing rooms as they feel the pressure a little bit more now.
Bologna's manager Arrigoni would have been pinching himself at the final whistle, as at one stage during some particularly frenzied Milan attacks he was seen slumped against the dug-out, looking at the ground with his back to the field.
It was certainly not all doom and gloom for Milan, as perhaps the result could be put down to some poor finishing and determined if extremely lucky defending from the visitors.
I do not think Ancelotti will be too worried at the moment, as it looks as if his side will definitely play better football than they did last season. Once the combinations are properly sorted, the goals should definitely start flowing.
Ronaldinho was definitely the stand out player for Milan, fashioning the equaliser and setting up several chances that were spurned by his strikers.
Bologna take the points and make a dream return to the top flight, with Di Vaio and Terzi both important for the away side. Valiani did not really figure much in proceedings until he popped up to score the screamer that sealed the match. Antolini is also worth mentioning, as he made several telling saves.
Berlusconi was seen in the stands, smiling from ear to ear when Ronaldinho was in full flight. He looked a little annoyed in the last few minutes. I think there would have been a lot of frustration in the Milan dressing room as well, as they come to terms with a performance that had everything but the goals.