Lazaros Christodoulopoulos was outstanding for Bologna and at the heart of much of their excellent attacking football so it was no surprise when he swept home the winner from the penalty spot.
Both sides came into the game in great need of victory. The home side, of course, are currently wedged within the relegation area while Cagliari were by no means out of trouble, sitting six points above the Rossoblu in 18th before kick off.
Each was cautious in feeling the other out in the early going with much of the opening exchanges being played out in midfield with Victor Ibarbo mis-cuing the first effort of the game wide on 14 minutes.
Ten minutes later, it took a timely block from Mikael Antonsson to keep Marco Sau quiet as the little striker looked to break the deadlock.
From there, it was the visitors who began to take a real stranglehold on proceedings with Gianluca Curci leaping to save from Matias Vecino and Albin Ekdal fizzed one just over the crossbar.
They did have to be wary of the threat the Felsinei posed on the counter and Robert Acquafresca twice had to be denied by Vlada Avramov in goal.
He had to be alert again before half time when Lazaros weaved his way past two challenges before sending a rocket towards goal that the goalkeeper got across to palm away to ensure it would remain level at the break.
The Bologna team talk at half time must have consisted of Davide Ballardini making sure his side knew how important it was to pick up three points with time running out and they responded with going on the front foot immediately but were almost caught cold when Vecino broke and had his low shot saved.
Lazaros curled a free kick over the top for Bologna before being denied by another brilliant save with 15 minutes to go after again jinking past defenders and letting loose.
Two minutes afterwards, the man of the match involved in everything was at the centre of controversy when the referee adjudged Daniele Dessena to have pushed him to the ground inside the box.
The spot kick was awarded and Lazaros stepped up to to provide the cool conversion and give his side a priceless lead.
The Isolani did have a chance to level as the minutes ticked down when a brilliant ball through the defence found Mauricio Pinilla in space and the Chilean drove a good effort at goal but once more the former Roma ‘keeper was equal to it in producing a solid stop that may have come off the post as his side went down to defeat.