Sami Khedira struck for the second successive game as Juventus won 1-0 at Lazio.
Khedira had been on target in the Serie A champions' opening 2-1 victory over Fiorentina, and the Germany midfielder settled this contest of few chances after 66 minutes.
Lazio had held firm until Paulo Dybala lofted a ball over the home defence and Khedira unleashed a low shot past Federico Marchetti in the home goal.
The game was played in temperatures that reached 90 degrees Fahrenheit and, before kickoff, fans held aloft banners to mourn those killed in Wednesday's earthquake in central Italy and a minute of silence was observed.
In the day's other match, Arkadiusz Milik and Jose Callejon each scored twice for Napoli in a 4-2 win over AC Milan.
Poland forward Milik scored twice in the first half before M'Baye Niang and Suso drew Milan level after the break. Callejon got the decider in the 74th and added another in stoppage time.
Milan ended with nine men as Juraj Kucka and Niang were sent off.