Goran Pandev kept 10-man AC Milan at arm's length in the race for second spot but Mathieu Flamini's early strike denied Napoli the chance to pull seven points clear in a 1-1 draw.
Flamini played both hero and villain as he briefly cut Napoli's lead over third place to a single point at San Siro before seeing red for a reckless challenge on Juan Camilo Zuniga in the second half.
Napoli were hoping to maintain their pursuit of Serie A leaders Juventus but Pandev's equaliser was only enough to cut the gap to eight points with six games remaining.
Cagliari made a perfect return to their temporary home in Trieste as Mauricio Pinilla scored twice to down struggling Inter Milan 2-0 at the Stadio Nereo Rocco.
Inter's week spent blaming officials' decisions for their disappointing campaign ended with another controversial penalty call as Pinilla fired the rehoused Sardinians ahead midway through the second half before hitting the winner 15 minutes from time.
Cagliari have left the doomed Stadio Is Arenas to move back to the Rocco, where they closed out last season, but the 600-mile journey north east did not adversely affect their players, who now find themselves in the top half of the Serie A table.
Roma held on for the final ten minutes with a man less to claim a potentially valuable 2-1 win from their trip to Torino.
The visitors twice led in the match - goals from Pablo Osvaldo and Erik Lamela sandwiching an equaliser from Rolando Bianchi - but were left sweating at the end after their Italy international defender Federico Balzaretti picked up a second yellow card for a foul on Alessio Cerci.
Torino could not make the most of their numerical advantage though as Roma claimed a victory that moves them level on 51 points with fifth-placed Lazio, who play host to runaway leaders Juventus on Monday night.
Udinese moved within three points of the Europa League places after Luis Muriel scored twice in a 3-0 victory at Parma.
Bianconeri coach Francesco Guidolin was worried about visiting the Stadio Ennio Tardini without his suspended 20-goal striker Antonio Di Natale, but Muriel allayed his fears with a coolly-taken brace in the first half.
Parma, who dropped into the bottom half of the table, were at a loss for ideas after the break and Roberto Pereyra compounded their misery with a third goal on the hour mark.
Catania's hopes of competing in Europe next season suffered a blow as they drew 0-0 at lowly Chievo.
In an even encounter, the visitors had the better opportunities to break the deadlock but a combination of poor finishing and Chievo goalkeeper Christian Puggioni making several fine saves proved their undoing.
Palermo saw their Serie A survival hopes suffer a setback as they were held to a 1-1 draw at home by Bologna.
Josip Ilicic gave the hosts a flying start at the Stadio Renzo Barbera with a goal after just five minutes, but Manolo Gabbiadini brought Bologna level soon after.
Matuzalem spared Genoa's blushes with a fortunate equaliser in a 1-1 draw in the Derby della Lanterna as ten-man Sampdoria missed the chance to complete a rare Serie A double.
Samp were in no mood to do their city rivals any favours in their battle to beat the drop and Eder's improvised free-kick put Delio Rossi's men on course to follow up November's 3-1 derby victory and push Genoa closer to relegation.
But Matuzalem pounced on a mistake from Samp goalkeeper Sergio Romero, after Andrea Costa had seen red, to keep the Rossoblu within two points of 17th-placed Siena with six games remaining.
Information from the Press Association was used in this report