Federico Chiesa scored a brace as Juventus inflicted a first league defeat this season on Serie A leaders AC Milan, ending their 27-match unbeaten run with a 3-1 win on Wednesday.
Stefano Pioli's side maintained their one-point advantage over city rivals Inter Milan who missed a chance to go top with a 2-1 loss at Sampdoria.
AC Milan had been unbeaten since before the coronavirus lockdown last March, with a run of 12 matches without defeat to complete last season where they finished sixth, and 15 games this campaign.
But Chiesa, who joined from Fiorentina last October, bagged his first brace for the champions, scoring on 18 and 62 minutes in the San Siro with Weston McKennie getting a third with quarter of an hour to go.
"This defeat hurts," said Pioli.
"If there is an opponent against whom we have suffered it is Juventus, who have won the Scudetto for nine years in a row.
"But understanding how bad you feel after a defeat will also help us grow."
The hosts, chasing their first 'Scudetto' since 2011, had been hit hours before kick-off with the news that forward Ante Rebic and midfielder Rade Krunic had tested positive for Covid-19.
The absence of the pair was a blow for the side already without key players including their injured top scorer Zlatan Ibrahimovic for an eighth league game.
Juventus pair Alex Sandro and Juan Cuadrado were also out with coronavirus as the champions moved up to fourth, seven points behind Milan, but having played a game less.
"I saw the spirit of a team that wants to lead and win," said Juventus coach Andrea Pirlo.
"This match was crucial for us."
Chiesa has come into his own for Pirlo's side who had been dependent on Cristiano Ronaldo's goals this campaign.
Paulo Dybala provided the assists for both Chiesa's goals.
Chiesa rattled the woodwork minutes before picking up a clever Dybala back-heel flick to finish off after 18 minutes.
Rafael Leao send through for Davide Calabria to grab the equaliser four minutes before the break to keep Milan's hopes alive.
But Dybala again teeded up Chiesa to rifle in the second before the pair were replaced by McKennie and Dejan Kulusevski.
Kulusevski provided the pull back for McKennie to seal the victory after 76 minutes.
- Inter miss out in Genoa -
Inter's eight-match winning streak came to an halt earlier under the rain in Genoa.
Alexis Sanchez missed an early penalty for Antonio Conte's side who were tripped up by goals from former Inter players Antonio Candreva and Keita Balde.
"I'm sorry because I think we deserved something more. Lady luck was not on our side today," said Conte after their second league defeat this season after Milan last October.
Inter's leading scorer Romelu Lukaku started on the bench as the forward recovers from a muscular problem.
Sanchez started in the Belgian's place but missed the chance to give the visitors an early advantage with Emil Audero saving a penalty.
But Candreva made no mistake from the spot after 22 minutes, sending Samir Handanovic the wrong way after Samp were awarded a penalty for a Nicolo Barella handball.
Keita Balde added a second after 38 minutes following good work from Mikkel Damsgaard, the Danish winger sending the Senegalese forward through to coolly finish.
Lukaku came off the bench with just over an hour gone, two minutes before Stefan de Vrij's header from a Marcelo Brozovic corner reduced the deficit for the visitors.
Third-placed Roma closed the gap on Inter to three points, with a 3-1 win at bottom side Crotone with Borja Mayoral scoring twice and Henrikh Mkhitaryan adding a third from the penalty spot.
Sassuolo beat Genoa 2-1 to move fifth ahead of Napoli who fell to a shock defeat by the same scoreline to 10-man Spezia, for their first loss in their newly-named Diego Armando Maradona Stadium.
"I don't know how it's possible to lose a game like this, we had many shots on goal, I had a dozen myself," said Napoli captain Lorenzo Insigne.
"I'm seeing a schizophrenic Napoli," blasted coach Gennaro Gattuso.
"It's not just bad luck, this season we're throwing away incredible matches. And that makes me furious."
Seventh-placed Atalanta beat Parma 3-0 to stay ahead of Lazio who got back winning 2-1 against Fiorentina.