Napoli took full advantage of Roma's defeat to Juventus on Sunday with victory over Sampdoria at the Stadio San Paolo on Monday.
Roma were beaten 3-0 by leaders Juventus and Napoli now sit just two points behind Rudi Garcia's men thanks to a Dries Mertens brace.
While they remain 10 points off the summit, Benitez's side are unbeaten in five league matches ahead of their clash with in-form Verona on Sunday.
Kaka became the 10th Milan player to reach the 100-goal mark for the club with a brace against Atalanta at San Siro.
He scored either side of half-time before Bryan Cristante registered his first for Milan to help them to a first win in four league matches, which follows the announcement of coach Massimiliano Allegri that he will leave at the end of the season.
Parma moved within two points of Torino thanks to a 3-1 win over Giampiero Ventura's charges at the Stadio Ennio Tardini
After Ciro Immobile put the visitors ahead, goals from Marco Marchionni and Alessandro Lucarelli ensured Parma were on top at the break.
There was time for Amauri to score his first goal in 23 Serie A appearances as Parma made it seven league games unbeaten.
Bottom side Catania picked up a vital win in their relegation fight, edging Bologna 2-0 thanks to goals in either half from Gonzalo Bergessio and Francesco Lodi.
Coach Luigi De Canio will have been buoyed further by Sassuolo's defeat to Genoa, with just three points separating the bottom five sides.
First-half goals from Alberto Gilardino and Andrea Bertolacci proved too much for Sassuolo, while Udinese's disappointing season continued with a 3-1 home defeat to Verona.
Luca Toni scored twice within the opening 40 minutes and, while Roberto Pereyra pulled a goal back before the break, Juan Iturbe killed off any hopes of a comeback as Verona moved fifth thanks to their fourth win in five games.
To add insult to injury, Udinese stalwart Antonio Di Natale confirmed his plan to retire at the end of the season having been at the club since 2004.
Verona's one-place jump was confirmed by Inter's 1-0 defeat against Lazio in Monday's late game as Edy Reja marked his return to the club with a victory.
Reja was confirmed as Vladimir Petkovic's replacement on Saturday and his side picked up three points thanks to Mario Klose's winner nine minutes from time.