Marco Di Vaio came back to haunt his former employers as he bagged a brace in Bologna's shock 2-0 win at Juventus on Saturday.
Still reeling from their defeat by the same scoreline at lowly Lecce last week, Juve failed to heed coach Luigi Delneri's warning that they needed to show an improved attitude if they are to succeed.
Despite having the better of the game, hitting the post and having a shot cleared off the line, Juventus fell to a pair of strikes from former striker Di Vaio.
It was sweet revenge for the veteran forward who spent two years at Juve but never managed to cement a regular starting berth.
"We continue to do well and play well and stay compact, it was a great performance and we're delighted," he said.
For the hosts it is now six defeats in their last 10 league matches and their hopes of qualifying for the Champions League, or even the Europa League, next season are quickly slipping away.
They were unsurprisingly jeered from the field by their own fans and Delneri admitted they need to improve.
"The problem is that we all need to work on being more of a team but maybe we lack serenity," he said.
"I can't say that I've lost the team in the last two weeks (since beating Inter Milan), it's a very difficult season for the team and I'm sorry for the fans who deserve more.
"This will be a year of great tension and sufferance if we continue like this."
Bologna coach Alberto Malesani said he felt it'a only a matter of time before Juve kick into gear.
"In the first half we didn't give away many chances apart from freekicks but in the second we saw how the team grew and after a day like this we'll strike fear into others," he said.
"(Juve) were incredibly strong physically, they're one of the most impressive teams alongside Milan but maybe they have a block.
"I like Juve, they've signed great players but they're doing worse than expected. If they unblock themselves, they'll be really strong."
Juve had by far the better of a dull first period.
Bologna goalkeeper Emiliano Viviano was first called into action inside the first 10 minutes as he had to punch an inswinging corner off his line.
On 14 minutes Giorgio Chiellini won a 50-50 challenge and teed up Alessandro Matri, but the forward got his sights muddled up and curled his shot well wide.
Felipe Melo tried his luck from outside the box with Viviano pushing the ball away and then getting up quickly to smother Vincenzo Iaquinta's rushed follow-up.
Iaquinta came closest to breaking the deadlock just before the break as a ricochet luckily fell to him but his bobbled effort came back off the post.
Having shown nothing in terms of attacking threat in the first half, Bologna took a shock lead four minutes into the second.
Di Vaio ran onto an opportunist ball over the top, shrugged off a weak challenge from Andrea Barzagli and then toe-poked the ball over the onrushing Marco Storari under pressure from Chiellini.
Juve's response wasn't exactly pulsating but they should have equalised just past the hour mark, only for Leonardo Bonucci to fail to make firm contact with Alessandro Del Piero's free-kick from two yards out, allowing a Bologna defender to hack clear.
And on 66 minutes Di Vaio made them pay again as he pounced on Riccardo Meggiorini's back-heel and beat Bonucci and Zdenek Grygera before shooting inside Storari's near post.
Suddenly Juve started to push and Barzagli sent a volley just wide while Bonucci won a header that he also sent the wrong side of the upright.
Six minutes from time Luca Toni looked to have scored for Juve as he turned home Simone Pepe's cross from six yards but Daniele Portanova somehow cleared the ball off the line while falling backwards.