Victor Osimhen scored twice as Napoli began the defence of their Serie A title by coming from behind to win at newly-promoted Frosinone.
The striker’s league-leading 26 goals last season helped Napoli to a first title since 1990, and he began the new campaign in similarly prolific fashion.
Abdou Harroui’s early penalty gave the hosts a shock lead but Matteo Politano levelled from the edge of the box.
Osimhen fired Napoli ahead before the break and steered in a second late on.
The 24-year-old, who has been linked with several of Europe’s biggest clubs this summer, crashed home a vicious strike off the underside of the bar before beating the Frosinone offside trap to seal victory with 11 minutes to go.
The win was far from routine for Napoli as the hosts, promoted as Serie B champions, went close to an equaliser before Osimhen’s second when Jaime Baez’s free-kick struck the post.
The champions had started badly when Jens Cajuste tripped Baez to concede a spot-kick, but they fought back to earn new boss Rudi Garcia victory in his first league game in charge.
The Frenchman took over during the summer, succeeding title-winning manager Luciano Spalletti, who stepped down and has since replaced Roberto Mancini as Italy boss.
Champions League runners-up Inter Milan, who finished third in Serie A last season, also began with a victory as Lautaro Martinez scored in each half in a 2-0 win over Monza.
Juventus get their campaign under way at Udinese on Sunday, as Roma host Salernitana and Lazio visit Lecce, while AC Milan start with a trip to Bologna on Monday night.
