It was a good day for debutants in Italy's Serie A as new faces at Juventus and Atalanta gave their teams a winning start to the league season.

New Juventus coach Thiago Motta surprised fans by handing a debut to youth academy graduate Samuel Mbangula on Monday and the 20-year-old winger responded by scoring the opening goal in a 3-0 win over Como.

Mbangula cut in from the left in the 23rd minute and slotted a low drive into the far corner to give Juventus the lead.

US international Timothy Weah scored the second for the Turin club when he smashed a shot in off the underside of the bar just before halftime. It was the American's first league goal for the club.

Andrea Cambiaso added a third in injury time to pad the scoreline in Cesc Fàbregas' first league game in charge of Como since taking over as head coach this offseason.

Atalanta routs Lecce

New signings Mateo Retegui and Marco Brescianini both scored twice as Atalanta routed Lecce 4-0 in a blistering start to its campaign.

Brescianini joined last season's Europa League winners from Frosinone just three days ago and Retegui was signed last week from Genoa.

Brescianini got the opener when the midfielder pounced on a parried save by goalkeeper Wladimiro Falcone after 35 minutes and then Retegui doubled Atalanta's lead with a powerful header on the stroke of halftime.

Retegui got the third from the penalty spot 12 minutes into the second period and then Brescianini took advantage of gaping holes in the Lecce defence to make it four after 65 minutes.

The result means the Bergamo club sits top of the Serie A table on goal difference after one round.