A Leonardo Bonucci penalty in each half proved enough for Massimiliano Allegri's side, making it back-to-back wins in the league after it beat Fiorentina 1-0 before the international break.
Lazio was without star striker Ciro Immobile and it showed as the Biancocelesti struggled to create much in the way of chances.
Maurizio Sarri would have been hoping to do better against his former club, with his team now having won just twice in its past seven games in all competitions.
Danilo was forced off with an injury for the visitors after 15 minutes after a strong challenge from Elseid Hysaj, with Dejan Kulusevski replacing the Brazilian.
Juventus had its first penalty in the 22nd minute after Danilo Cataldi was judged to have fouled Alvaro Morata in the box after a video assistant referee (VAR) review, which Bonucci coolly dispatched past Pepe Reina.
Morata should have made it two just before half-time when Juan Cuadrado lifted a delicate ball into the box, only for the Spain striker's scissor-kick to fly over the bar.
Juve had its second penalty with 10 minutes remaining after Federico Chiesa rounded Reina, only to be hacked down by the goalkeeper before he could score, and Bonucci made no mistake to seal the win.