Atalanta moved back second ahead of Napoli with a 2-0 win over relegation candidates Benevento.
Antonio Conte's side are on course for a 19th Serie A title and first since 2010.
Defender Stefan de Vrij and midfielder Matias Vecino have contracted the virus following the positive cases of defender Danilo D'Ambrosio and goalkeeper and captain Samir Handanovic earlier this week.
Fiorentina next week host second-placed AC Milan before a trip to lowly Genoa who earned a point in a 1-1 draw at home against midtable Udinese.
European football matchday: Chelsea travel to Leeds United; Bayern Munich at Bremen in most-contested fixture
Chelsea are in the fourth Champions League spot, two points ahead of West Ham, who have a game in hand.
Serie A: Juventus forward Paulo Dybala expected to be out for 20 days after picking up knee ligament injury
In a statement, Juventus said that Argentina forward Dybala had undergone examinations at the club's medical centre which revealed an injury to "the medial collateral ligament of the left knee with recovery times of approximately 15/20 days".
Serie A: Rafael Leao scores fastest goal in league’s history as AC Milan beat Sassuolo; Atalanta thrash Roma 4-1
Portuguese youngster Leao’s goal beat the previous record of eight seconds set by Piacenza’s Paolo Poggi against Fiorentina in 2001
AC Milan pulled five points clear of city rivals Inter Milan and Sassuolo, with AS Roma and Juventus six points adrift.
Inter played with the ferocity coach Antonio Conte had been demanding and Sassuolo barely had a sight of goal apart from a curled effort from Filip Đuričić that hit the outside of the right post.
Serie A: Ageless Ibrahimovic's brace helps AC Milan beat Napoli; Inter Milan come from behind to defeat Torino
Zlatan Ibrahimovic scored twice to raise his total to 10 goals in six games played as Milan won 3-1 at Napoli on Sunday.
What to watch in European football today: Leicester hoping to spoil Liverpool's record, Milan to test unbeaten run against Napoli
Liverpool have not lost their last 63 league games at home. That matches a club record set in December 1980 which was ended by a defeat to Leicester.
Serie A table-toppers AC Milan cancel training after coach Stefano Pioli tests positive for COVID-19
AC Milan say Pioli is showing no symptoms and that the 55-year-old coach has gone into isolation at home.
Serie A: Sassuolo climb to second after beating Bologna; Edin Dzeko scores brace in Roma's comeback win over Benevento
Roberto de Zerbi's Sassuolo had been trailing 3-1 after an hour, but three substitutions, including a first start for French midfielder Maxime Lopez, rescued three points for the visitors.
Around European football on Sunday, Gareth Bale would be hopeful of featuring against West Ham in his return to Tottenham. In Spain, Valencia play Villarreal in derby.
Di Francesco signed a contract through June, 2022. He previously coached Pescara, Lecce, Sassuolo, Roma and Sampdoria.
Serie A: Ciro Immobile scores, taking tally to 35 goals, as Lazio beats Brescia 2-0 in race for second spot
Immobile is just one off equaling the all-time record of 36 goals in a Serie A season, set by Gonzalo Higuain when he was at Napoli in 2015-16.
Serie A: Romelu Lukaku scores brace as Inter Milan beat Genoa to stay in title race; Napoli earn win against Sassuolo
Both Inter and Genoa were desperate for the points but chances were few and far between.
It was AC Milan’s seventh victory in the nine games since Serie A resumed following the pandemic-enforced shutdown and moved the team up to fifth.
In their last three matches Juventus have scored seven goals, conceded nine and taken two points. They have twice squandered two-goal leads in the process.
It was Juventus' third straight match without a win after a 4-2 loss against AC Milan — after going 2-0 up — and a 2-2 draw against Atalanta.