Bologna striker Adailton scored three minutes into injury time to prevent Juventus going top of Serie A.
With Sampdoria having beaten previous leaders Inter Milan yesterday, Juve could have replaced the Blucerchiati atop the standings with a win and seemed well placed when David Trezeguet put them ahead after 24 minutes.
But Bologna never gave up and salvaged a deserved point when Adailton converted Pablo Osvaldo's late cross.
After starting the season with four straight wins it was the second draw in a row for Ciro Ferrara's team, who were held 2-2 at Genoa in midweek, and they will need to perform better in Wednesday's Champions League clash at Bayern Munich.
In truth, Juve were slightly unlucky to come away with only a point on Thursday and they continued in a similar fashion at the start of today's game.
They should have gone ahead in the 12th minute when Amauri drew a good save from Emiliano Viviano but, with Trezeguet lurking, he really should have passed.
Just a minute later the French striker went close, receiving a long ball from Mauro Camoranesi and forcing a great save from Viviano with a strike from just inside the box.
And after 17 minutes he was just inches away again after he got too much on Jonathan Zebina's cross and deflected the ball out of play.
The goal which Juve and Trezeguet deserved came shortly after.
Zebina advanced down the right and into the area before shooting at goal.
His effort was deflected by a defender and by Viviano, but Trezeguet was on hand to follow up from two yards.
Bologna reacted well to going behind and started to come into the game as an attacking force.
After the half-hour mark, Marcelo Zalayeta came close with a header and even had the ball in the net via Juve defender Giorgio Chiellini.
Chiellini, though, was under pressure from Marco Di Vaio, who was adjudged offside and the goal was chalked off.
Juventus slowed the game down after the break, seemingly happy to protect their lead, but they still created chances, the best coming when Felipe Melo drew a fantastic save from Viviano on the hour.
At the other end, Chiellini came to the rescue of his goalkeeper after Gianluigi Buffon missed a cross allowing Di Vaio to turn the ball towards goal. Chiellini got back to head clear.
After 72 minutes, Buffon repelled an effort from Giacomo Tedesco and Adailton should have done better than to blaze the rebound over the bar.
Camoranesi had two great chances in the closing stages to extend his side's lead, heading first against the post and then wide.
And the misses proved costly when Adailton converted Osvaldo's cross from the right to steal a point for Bologna.
