Inter Milan continued their pursuit of Serie A leaders Juventus by moving above Napoli into second place thanks to victory at Bologna.
Andrea Ranocchia gave the visitors the lead in the 27th minute before Diego Milito added a second just after the half-time break.
Nicolo Cherubin replied immediately, but Esteban Cambiasso scored his first goal of the season minutes later to seal Inter's fifth consecutive win and keep them four points shy of Juve at the top of the table.
The home side started the brighter with Alberto Gilardino and Alessandro Diamanti both making nuisances of themselves in front of the Inter defence.
The duo combined in the 12th minute with Diamanti's shot going wide of the right-hand post after an intelligent pass from Gilardino.
Inter drew first blood in the 27th minute when Cambiasso's sweeping free-kick was met by the head of Ranocchia, who looped the ball back across Federico Agliardi and into the opposite corner.
Bologna tried to find an equaliser, but became increasingly frustrated at their inability to find a way through a disciplined Inter defence, bossed by Walter Samuel.
When Gilardino did get through, he claimed a penalty having tumbled in the area, but the linesman's flag was raised to curtail his appeals.
In the 53rd minute, Inter doubled their lead with route one football paying dividends on an increasingly soggy pitch.
Samir Handanovic punted the ball forwards and Rodrigo Palacio picked it up, cutting inside a defender before passing into the path of Milito, who swept it in with just one touch.
Five minutes later, Gilardino's volley from the edge of the penalty area was pushed behind for a corner by Handanovic.
From the subsequent set piece, Diamanti lifted the ball into the centre where Cherubin was left alone in front of Handanovic to nod Bologna back into the game.
Bologna coach Stefano Pioli and Inter's assistant Beppe Baresi were both sent off as tensions rose between the benches in the 62nd minute, before Cambiasso's goal settled Inter's nerves.
The Argentinian latched onto a neat touch from Palacio before chipping the ball over Agliardi from eight yards out.
This time, Bologna were unable to summon the strength to recover, with Cambiasso and Ricky Alvarez both squandering late chances for the Nerazzurri.