Inter Milan Serbian midfielder Dejan Stankovic celebrates with Samuel Eto'o after scoring during Bologna match
After a difficult first half to the season, Inter were looking like their old selves again as they cruised to victory against their troubled opponents, leaving them perilously close to the drop zone.
Dejan Stankovic, Diego Milito and a Samuel Eto'o brace -- taking his tally to 23 goals in 26 games this season -- moved Inter up to fourth, for a day at least, and just eight points behind leaders Milan having played a game less.
It was a special night of celebration for Inter as captain Javier Zanetti equalled Giuseppe Bergomi's record of 519 Serie A appearances for the club.
Henry Gimenez scored Bologna's late consolation in a terrible week for the club who were hit with a three-point deduction for failing to pay taxes and player salaries.
It was vintage Inter from the off as Leonardo's team romped to their fourth straight win under the Brazilian, who took over from the sacked Rafael Benitez at the end of December.
Milito had an early chance but somehow managed to hit the woodwork from just two yards out while Bologna goalkeeper Emiliano Viviano, a reported Inter target, made excellent saves to deny Eto'o and Maicon.
Inter went in front on 20 minutes as Eto'o burst past a defender and then slid a pass into Stankovic to score into an unguarded net, although TV replays suggested the Serbian may have been offside.
Ten minutes later and the hosts doubled their advantage as an inch-perfect pass from Thiago Motta sent Milito scampering away before teasing a defender and then finishing left-footed across Viviano, the ball passing through the goalkeeper's fingers.
Viviano may have been hoping his potential new employers missed that error while opposing keeper Luca Castellazzi seemed determined to show he's worth holding onto.
On 34 minutes Marco Di Vaio had a great chance breaking beyond the Inter defence but Castellazzi made a splendid one-handed save from his 20-yard shot.
And moments later he made a sprawling save to stop a Di Vaio free-kick.
Inter seemed to have taken their foot off the peddle after the break as Bologna pushed for a route back into the game.
Gimenez shot narrowly over and then Di Vaio flashed another free-kick barely an inch past the post.
But Bologna's hopes of dragging themselves back into the game were killed by a wonderful goal on 63 minutes.
Eto'o teased a defender out on the left, nutmegged him in passing to Milito who sent a first time backheel into the Cameroon forward's run and Eto'o finished crisply into the bottom corner.
Eto'o put the final nail in Bologna's coffin with a sweetly-struck free-kick into the top corner.
Gimenez then prodded home 13 minutes from time but the game was already over.
Napoli failed to capitalise on their chance to close in on AC Milan in a dull and frustrating stalemate.
The point keeps the southerners second in Serie A, but still three points behind Milan who have a game in hand away to Lecce on Sunday.
Napoli came into this game with plaudits ringing in their ears following last week's 3-0 win over Juventus, after which coach Walter Mazzarri had said it would be difficult for them to ever play better than that.
He was not wrong as they never even got close against La Viola.
However, Mazzarri insisted he was happy with his team.
"I'm not looking at the table, we're in competition with ourselves. We need to improve and we are improving," he said.
"We gave our all today, we were balanced without giving away anything at the back. We're high up in the league and all we must do is continue on this path."