Champions Juventus face a test of their title-defending credentials on Saturday when a resurgent Inter Milan travel to Turin with a real chance of reducing their four-point deficit to the leaders.
Juventus extended their unbeaten streak to 49 matches after a late Paul Pogba header helped secure a 2-1 win away to Bologna on Wednesday as Napoli slipped up at Atalanta and Inter moved up to second with a 3-1 win at home to Sampdoria.
A 50th match without defeat - Juve's last reverse came against Parma in May 2011 - will be expected by fans of the Old Lady, but Inter's resurgence has slashed the odds.
Inter's sixth win on the trot came in convincing and timely fashion ahead of a fixture billed as the 'Derby d'Italia'.
Indeed, Inter have peaked so well for this game conspiracy theorists might suggest that canny 36-year-old coach Andrea Stramaccioni, who recently waved off comparisons with Jose 'The Special One' Mourinho, had timed it deliberately.
Argentine midfielder Esteban Cambiasso admits Juve's "good run" deserved applause, but said Inter's good form is a reflection of their high expectations.
"It'll be an important match, and definitely a different one from the others," he told inter.it. "This Inter team is now in the situation that it should be in."
While Inter seem to be relishing the challenge, Juve could be suspected of feeling the pinch ahead of a possible 50th match without defeat.
On Thursday it was announced coach Angelo Alessio, the caretaker in the absence of the suspended Antonio Conte, would not be talking to the press prior to the game - the second such decision this week on the part of the club.
Juve defender Andrea Barzagli was not scared to admit Stramaccioni's Inter, boasting the attacking talents of Diego Milito, Antonio Cassano and Rodrigo Palacio, have made them sit up and take notice.
"Now they have a new, young coach who is determined to stand apart and is doing well with Inter," Barzagli told Sky Sport.
"As a result, they've signed some good players who want to do well for the club and that is why I think Inter really want to do something this year."
While AC Milan's Stephan El Shaarawy became the league's top scorer on Tuesday, Juventus (along with Roma on 22 goals) and Inter (19) have the best scoring records in the league.
Juventus's defence has leaked only five goals, the meanest in the league, in 10 games, to Inter's nine.
Hopefuls eye momentum
On Saturday Milan, 12th at 17 points adrift of Juve, host Chievo at the San Siro with only one thing on their minds: "We have to beat Chievo if we are to start climbing up the table," said midfielder Kevin Constant.
Napoli, who dropped to third at six points behind Juve, could yet be without top striker Edinson Cavani when Torino visit on Sunday, the Uruguayan having missed the trip to Bergamo due to an injury niggle.
After a sluggish start to the season Fiorentina are enjoying a purple patch and moved up to fifth thanks to a 1-0 win away to Genoa Thursday, three days ahead of hosting Cagliari.
Zdenek Zeman's Roma, meanwhile, host Palermo in Sunday's late match hoping to put their recent setbacks behind them.
Two consecutive 3-2 defeats, to Udinese then Parma on Wednesday, have left the Giallorossi seventh, 14 points adrift of Juve and for many their defence is to blame.
While Roma, along with Juventus, have scored a league-topping 22 goals they have conceded the most goals, at 19.
Italy Serie A fixtures
Milan v Chievo
Juventus v Inter Milan
Pescara v Parma
Bologna v Udinese
Catania v Lazio
Fiorentina v Cagliari
Sampdoria v Atalanta
Siena v Genoa
Napoli v Torino
Roma v Palermo