The Rossoblu had already come back from 2-0 down to upset Roma 3-2 back in Week 3 so entertainment was always on the cards. The result does nothing to squash speculation about under fire Zdenek Zeman's long term prospects as Roma coach.
Roma travelled without the injured Daniele De Rossi and Mattia Destro, while Erik Lamela served a suspension. Miralem Pjanic was fit to return and full back Vasilis Torosidis was on the bench just days after joining from Greek side Olympiakos.
Bologna almost equalised straightaway as Mauro Goicoechea beat away Alessandro Diamanti's thunderous shot.
The Rossoblu did draw level on 17 minutes. Diego Perez's high ball found Manolo Gabbiadini whose shot in between two markers was only parried by Goicoechea. Alberto Gilardino followed up to stab in the rebound from close range.
Less than 60 seconds later the Giallorossi were back in front. An unmarked Pablo Osvaldo took advantage to head in cross.
Bologna equalised once again on 26 minutes. Poor marking from Nicolas Burdisso allowed Gabbiadini to turn in the area and send a low shot which beat Goicoechea at his near post.
Diamanti crossed for Gilardino to volley into the side netting and a Michael Bradley rocket went just wide to end an enthralling first half.
Marco Motta intercepted a dangerous Pjanic cross meant for Florenzi as the second half picked up where the first left off.
Bologna were forced to introduce Cristian Pasquato for the injured Gabbiadini. The frontman made an immediate impact. Goicoechea came for a cross but got mixed up with Burdisso and only succeeded in pushing it out to the substitute, who hooked the ball into the net.
Roma lost Federico Balzaretti to injury, but were let off the hook with some more poor marking by the home side. Totti lofted a free kick into the box and onto the head of Panagiotis Tachtsidis, who guided the ball past a hapless Agliardi.
Both sides had chances to win it. Agliardi pushed an Osvaldo header off the line and Diamanti curled a left footed effort onto the post. Bologna's frustrated frontman then rattled the cross bar with a powerful free kick deep into stoppage time.
Bologna: Agliardi; Motta, Antonsson, Sorensen, Morleo; Perez; Taider (Krhin 64), Diamanti, Kone, (Abero 86) Gabbiadini; (Pasquato 49) Gilardino
AS Roma: Goicoechea; Piris, (Torosidis 73) Burdisso, Castan, Balzaretti; (Dodo 57) Bradley, Tachtsidis, Florenzi; (Marquinho 58) Pjanic, Osvaldo, Totti
Goals: Florenzi 9 (R) Gilardino 17 (B) Osvaldo 18 (R) Gabbiadini 26 (B) Pasquato 54 (B) Tachtsidis 74 (R)