Goran Pandev ended his recent goal drought with a first-half brace to secure a 2-0 away win at Genoa which put Napoli top of Italy's Serie A on Saturday.
Ahead of the rest of the weekend fixtures, Rafael Benitez's side have a one-point lead on Roma and a three-point advantage on Inter Milan and Juventus.
Juventus face Torino away in the city derby in Sunday's early match where Antonio Conte's men would have to win and score several goals if they are to take command of the league.
Inter face Cagliari away in one of five afternoon's games while Roma, who began the weekend top of the table with a two-point lead on their rivals, host Bologna in the late game.
Pandev had gone nine games without hitting the net since scoring against Pescara last April.
But with Benitez resting forwards Marek Hamsik and Gonzalo Higuain ahead of Tuesday's Champions League clash against Arsenal at the Emirates, Pandev made the most of a rare start.
The Macedonian international opened the scoring in the 14th minute when he pounced on a poor backpass from Slovakian midfielder Juraj Kucka to beat Mattia Perrin with a clinical left-foot strike.
Pandev doubled Napoli's lead barely 10 minutes later when he finished off the good work of fellow forward Lorenzo Insigne.
With Duvan Zapata still short of full match fitness, Benitez replaced the Colombian striker with Higuain in the 59th minute, but the Argentinian international failed to threaten Perrin in the hosts' net.
Despite the prospect of Roma regaining their two-point advantage on Sunday, Benitez said: "I'm really happy because we got the win against a team that was determined and showed a lot of character and quality football.
"It's just a shame we didn't put the game beyond reach earlier with a third goal, we had the opportunities."
Explaining his rotation policy, the Spaniard added: "When you have three games in the space of a week, it's normal.
"If a player is available and I have a chance to use him then I will. For example, I used Zapata tonight and it was his first game, but he did well playing alongside Pandev."
AC Milan, meanwhile, claimed only their second win in six games when Valter Birsa's 46th minute goal secured a 1-0 win at home to Sampdoria.
Sampdoria, third from bottom, have yet to win this season and their fourth defeat of the campaign was even more painful as Milan signed Birsa from the visitors' city rivals in the off season.
The win moved Massimiliano Allegri's injury-ravaged side up to ninth place although Milan could drop again after the remainder of the weekend fixtures.