Inter Milan took advantage of their title rivals slipping up with a thumping 4-0 win over Cagliari on Sunday which ensured they moved top of Serie A.
Reigning champions Inter moved a point ahead of local rivals AC Milan with a statement performance at the San Siro against the Sardinians who had goalkeeper Alessio Cragno to thank the hosts didn't run up double figures.
Inter, who racked up 15 shots on target, hit the bar and missed a penalty, are also four points ahead of former leaders Napoli who slipped back to fourth following a shock 1-0 home defeat at the hands of surprise team Empoli.
"We saw a lot of good teams struggle after their European matches so we knew we needed to be focused. The boys were brilliant right from the start," said Inzaghi to DAZN.
"We're top of the league and in the Champions League last 16 after 11 years, it's hard to do much better."
Cagliari are second-from-bottom and their supine performance, even with a number of absences, so angered manager Walter Mazzarri that he left his post-match interview with DAZN after answering just one question.
Martinez opened the scoring with a bullet header from Calhanoglu's corner just before the half hour, and Inter were poised to open a two-goal half-time lead after Cragno brought down the marauding Denzel Dumfries.
Inter put the match to bed with two brilliant goals in two minutes, with Calhanoglu drifting in from the left flank and lashing home a powerful strike before Martinez made it 10 for the season in the 68th minute, collecting Barella's floated pass and dinking home a delicate finish.
- Empoli stun Napoli -
Patrick Cutrone's bizarre winner with 20 minutes remaining in Naples fired promoted Empoli seventh, above Roma and Lazio who lost 2-1 at Sassuolo, and hit Napoli's bid for a first title since the days of Diego Maradona.
Cutrone rose highest for a corner and his flick flew at Andre-Frank Zambo Anguissa, who minutes after his return from injury headed his clearance into the back of Cutrone's head and then watched the ball fly back into his own goal.
It was an unfortunate way to lose for Napoli who had 30 shots, struck the bar through Eljif Elmas in the first half and had a Juan Jesus goal ruled out for offside nine minutes before Cutrone's winner.
"The goal was a set-piece play that we've been working on for a long time," joked coach Aurelio Andreazzoli.
Napoli held top spot before last weekend's matches but have now also been overtaken by Atalanta who moved third with their 2-1 win at Verona.
Napoli travel to Milan next weekend hoping to not fall further behind the pacesetters with key players either out or only just returning from injury.
- Atalanta's warning shot -
Atalanta are just three points behind Inter after coming back from Giovanni Simeone's 12th goal of the season with strikes in either half from Aleksei Miranchuk and Teun Koopmeiners at Verona.
A sixth straight league win on the road also has Gian Piero Gasperini's side seven points above fifth-placed Fiorentina in the race for the Champions League.
"Today we took a step forward, regarding mentality and determination, otherwise you don't win these kinds of matches," said Gasperini.
The hard-fought win will be a boost for Atalanta after they missed out on the last 16 of the Champions League.
They are in Monday's draw for the Europa League play-off round after finishing third in Group F behind La Liga outfit Villarreal and Manchester United.
