Leonardo's men 11 points behind rivals Milan
Catania boss Marco Giampaolo lined up a 4-1-4-1 formation, but was without regular first-teamers Marco Biagianti and Alessandro Potenza. Maxi Lopez, who had scored in the club's last two Serie A matches, once again led the line.
Meanwhile, the visitor's star striker Samuel Eto'o returned from a three-match suspension to partner Diego Milito up front, pushing Goran Pandev to the bench. Playmaker Wesley Sneijder and goalkeeper Julio Cesar remained sidelined.
The Sicilians were the more dangerous side early as Inter struggled to get a foothold on the match, but neither side could create a real chance in a rather dull and cautious first 20 minutes.
Right-back Pablo Alavarez tried a pot shot on goal from 25 yards, but Luca Castellazzi easily gathered the central effort. Simone Pesce's effort minutes later whizzed wide of the post after a promising counter-attack.
Milito was finding it difficult to gain any change from his opposition central defensive duo of Bellusci and Silvestre, being shadowed wherever he moved on the pitch and often fouling or being caught offside as the first-half edged towards its conclusion.
The referee blew the whistle to end a rather disappointing first-half as it ended 0-0 with little excitement occurring in the first 45 minutes.
The second-half began with more space afforded to both sides and Alejandro Gomez tested Castellazzi with a low drive after Cristian Chivu's poor clearance from a corner. Dejan Stankovic and Maxi Lopez traded long-range efforts at opposite ends.
Catania's Argentine forward was then denied by the quick reflexes of the Beneamata shot stopper as he tried to curl the ball in from the edge of the area. Eto'o finally got some freedom 63 minutes in, but his shot was eventually blocked after he cut back onto his right foot in the area.
Leonardo threw on more offensive punch with Goran Pandev however it was the Etnei who nearly opened the scoring with a save from Maxi Lopez's drive. At the other end Mariano Andujar was finally called into action being tested by Milito.
The Stadio Massimino then erupted as Gomez made the breakthrough. Stankovic cleared the ball off the line from Maxi Lopez's shot, but it fell straight to the winger who pounded it into the roof of the net.
Amazingly Inter responded immediately. Stankovic's cute pass found Cambiasso, who slotted past Andujar with ease to equalise with 15 minutes remaining. The result was completely turned around on 80 minutes as Maicon's outswinging cross found Cambiasso again and he nodded the ball over the line to take a 2-1 lead.
Italian international centre-back Andrea Ranocchia made his debut for the champions late on, replacing the tired Milito as they looked to hold onto the narrow lead.
Catania huffed and puffed for an equaliser, but suffered their second home loss of the season as they couldn't blow Inter's house down. Meanwhile, Leonardo's side are now 11 points behind leaders Milan in the Serie A standings.