Lazio ended 2012 in second spot in Serie A after winning 1-0 at Sampdoria on Saturday, while Inter drew with Genoa.
Struggling Genoa held Inter Milan to a 1-1 draw with a spirited performance at the San Siro.
Genoa soaked up the pressure and frustrated their hosts before going in front through Ciro Immobile in the 77th minute.
Inter's efforts were finally rewarded in the 85th minute with Esteban Cambiasso pulling them level, but Marko Livaja missed a glorious chance to win it as the Nerazzurri only managed to reduce the gap to Juventus at the top of the table to nine points.
Inter's draw meant Lazio moved up to second as Hernanes scored the only goal of a hard-fought away win against Sampdoria.
Hernanes netted just after the half-hour as Vladimir Petkovic's side beat the team bossed by former Lazio coach Delio Rossi.
The Brazilian was on hand after 31 minutes to net the opener and Lazio went on to claim all three points.
Two late goals saw Napoli end a chastening week with a flourish following a 2-0 triumph at 10-man Siena.
The Azzurri's pursuit of Juventus was derailed this week as the Italian Football Federation (FIGC) deducted two points from the club for a former player's involvement in match-fixing, while they then exited the Coppa Italia courtesy of a second home loss to Bologna in three days.
And it seemed like there would be more frustration in store as they failed to capitalise on their dominance until Christian Maggio broke the deadlock in the 86th minute, while Edison Cavani netted immediately after from the spot after Goran Pandev had been upended in the area by Felipe dal Belo.
It was just reward for the visitors, who end the year in fifth and 10 points behind Juventus, but Siena's afternoon was compounded in added time when Emanuele Calaio was sent off after needlessly elbowing Valeron Behrani.
In the night's late kick-off, a brace from Erik Lamela inspired Roma to a 4-2 home victory over AC Milan at the Stadio Olimpico.
Nicolas Burdisso broke the deadlock in the 13th minute with Pablo Osvaldo doubling Roma's lead 10 minutes later.
Lamela's double ensured there was no way back for the visitors, who at least grabbed late consolations through Giampaolo Pazzini and Bojan Krkic after Marquinho was sent off for Roma.
Stevan Jovetic struck a second-half brace as freescoring Fiorentina ensured they would finish 2012 in the Champions League places with a comfortable 3-0 victory at lowly Palermo.
Jovetic, who had been a doubt for the match due to a thigh problem, opened the scoring in the 50th minute and then doubled his side's lead with a penalty seven minutes from time.
Jovetic might have been celebrating a hat-trick in the final minute after Fiorentina had won another penalty, but centre-back Gonzalo Rodríguez took over spot-kick duties and confidently converted.
Parma came from behind to pick up a 2-1 win over Bologna which takes them up to eighth.
Frederik Sorensen's first goal of the season put Bologna in front in the 54th minute but goals from Jaime Valdes and Nicola Sansone earned Roberto Donadoni's side all three points.
Bologna drop to within three points of the bottom three with their 10th defeat of the season.
Elsewhere, a Gennaro Sardo own goal and an Alessandro Gazzi strike gave Torino a 2-0 home win over Chievo, while Atalanta and Udinese played out a 1-1 draw.