Reigning champions Inter came through what was supposed to be a tough test at the Stadio Olimpico with flying colours and are three points off the Scudetto pace with a game in hand.
Substitute Zaniolo decided a hard-fought encounter in Sardinia by stroking home Raoul Bellanova's cut-back in the 66th minute and moving Atalanta five points clear.
Edoardo Bove has had a defibrillator fitted after the Fiorentina midfielder's on-pitch cardiac arrest earlier this month, according to widespread Italian media reports on Tuesday.
Fiorentina earlier remained on Napoli's heels after their 1-0 home win over Cagliari in their first league match since midfielder Edoardo Bove's sudden collapse last weekend.
Edoardo Bove is conscious and alert in hospital after his sudden collapse which caused Fiorentina's match with Inter Milan to be called off, the Serie A club said on Monday.
Fiorentina's Serie A match with Inter Milan was stopped on Sunday after midfielder Edoardo Bove suddenly collapsed to the ground.
"It's too early to talk about the title. All we can do is look out for how we develop as a team, work to improve and win every match we play. But now is not the moment to talk about the title," said Lukaku.
Juventus remain the only unbeaten side in Serie A but their seventh draw of the season means they remain sixth in the standings and are now three points behind leaders Inter Milan. Milan stay seventh, six points behind Juve, though they have played one game fewer.
Simone Inzaghi's side are provisionally ahead of Napoli after netting all five of their goals in the opening 45 minutes at the Stadio Bentegodi through a Marcus Thuram brace and further strikes from Joaquin Correa, Stefan de Vrij and Yann Bisseck.
Inter Milan's Scudetto is easily Inzaghi's biggest honour since winning it as a player with Lazio 24 years ago, and comes after three years of off-field turbulence and serious financial problems which he has navigated with aplomb.
Goals from Francesco Acerbi and Marcus Thuram gave Inter a 17-point advantage over closest challengers Milan and secured their 20th league crown with five matches of the season remaining.
Inter Milan can secure their 20th Serie A title on Monday by piling on more humiliation on AC Milan in one of the most hotly-anticipated city derbies in years.
Empoli, who are battling relegation, opened the scoring after four minutes when striker Alberto Cerri headed in a close-range cross for what proved to be the winner.
The Champions League will have 36 teams in the group stage from next season, four more than this term.
Daniele De Rossi will stay on long-term as Roma coach, the Serie A club announced on Thursday, hours before their Europa League quarter-final decider with AC Milan.
"Evan is feeling better and is in good spirits. He will remain in the hospital for further observations," said Roma on social media, alongside a photo of Ndicka flexing his right bicep while sat upright in a hospital bed in Udine.
Play in Roma's Serie A match at Udinese on Sunday was abandoned after Evan Ndicka collapsed with an apparent problem with his chest.
Noah Okafor salvaged a hard-fought point for Milan in the 84th minute on a hot spring day in Reggio Emilia, but second-placed Milan still risk conceding the Scudetto to Inter in a hotly-anticipated derby despite coming back from two goals down.
Italy midfielder Frattesi poked home the decisive goal in the fifth minute of stoppage time in Udine to maintain Inter's 14-point lead at the top of the table with seven matches left in the season.
