Rome: A 2-1 win at Roma on Sunday placed Juventus in prime position for a record-extending ninth straight Serie A title.
Goals from Merih Demiral and Cristiano Ronaldo in the opening 10 minutes moved the Bianconeri two points ahead of Inter Milan, which was held 1-1 by Atalanta a day earlier, at the halfway stage of the season.
Poor defense by Roma contributed to both goals.
Gianluca Mancini left Demiral unmarked at the far post to redirect in a free-kick from Paulo Dybala only three minutes in at the Stadio Olimpico.
Then Jordan Veretout lost control inside his own area and reacted by fouling Dybala to set up a penalty from Ronaldo.
It was Ronaldo's ninth goal in his last six league matches, making him the most prolific scorer in Europe's top five leagues since the start of December.
Both Demiral and Roma midfielder NicolÃ² Zaniolo exited the game due to injuries before the break.
Diego Perotti pulled one back for Roma midway through the second half with a penalty following a VAR consultation to determine a hand-ball.
Roma forward Edin Dzeko hit the post just before Perotti's penalty.
Sampdoria fought back to beat fellow strugglers Brescia 5-1 and go five points above the relegation zone.
Brescia, who remain a point from safety, took the lead through Jhon Chancellor.
But Karol Linetty scored and set up the other goal for Jakub Jankto to put Samp ahead at the break.
Mario Balotelli thought he had levelled for Brescia but he was offside. He also missed several other chances.
Sampdoria extended their lead with Fabio Quagliarella's penalty after Brescia defender Massimiliano Mangraviti was judged to have handled the ball.
Gianluca Caprari sealed the match seconds after coming off the bench and Quagliarella added a fifth late on with a cheeky lob.
Spal remained bottom, three points from safety, after a narrow 1-0 loss at Fiorentina.
Gabriel Strefezza hit the woodwork for Spal before the break but German Pezzella headed in a corner with eight minutes remaining to end Fiorentina's four-match winless run.
Sassuolo were left five points above the drop zone after losing 3-0 at Udinese, while Torino beat Bologna 1-0 to go seventh.
Also, Hellas Verona moved up to eighth with a 2-1 win over Genoa.