2018 ScheduleAll times ET
Goals either side of the break from the Portugal international and Mario Mandzukic earned Juve their 12th win of an unbeaten start in the league.
Inter Milan survived a missed penalty as they won 2-1 at SPAL, their sixth win in a row in all competitions, with two goals from Mauro Icardi.
A team-by-team guide to the new Serie A season as Cristiano Ronaldo makes the move to the Italian top flight.
Juventus missed the chance to go seven points clear at the top of Serie A after being held to a 0-0 draw at struggling SPAL.
Patrick Cutrone scored twice as AC Milan won 4-0 at SPAL to keep up their recent good form.
Inter Milan's Serie A woes continued with Sunday's 1-1 draw at lowly SPAL stretching their winless run to seven matches.
Edin Dzeko ended his goal drought with the opener as Roma beat 10-man SPAL 3-1 on Friday evening.
Juventus kept up their pursuit of Inter Milan and Napoli at the top of Serie A with a 4-1 win against SPAL.