MILAN, Italy (Reuters) - Striker Oliver Giroud's first goals for AC Milan helped them to a comfortable 4-1 victory over Cagliari on Sunday as Stefano Pioli's team continued their perfect start to the new Serie A season.

In a goal-laden first half, Sandro Tonali broke the deadlock after 12 minutes, curling a sublime free kick into the net to give Milan the lead, before Alessandro Deiola headed the visitors level three minutes later.

Parity was restored for less than two minutes as Rafael Leao edged Milan back in front before Giroud scored his first goal for his new club after joining them from English Premier League side Chelsea in the close season.

The first-half scoring was not done there as Giroud converted from the penalty spot just before the interval to make it 4-1.

Pioli's side cruised to their second successive win, finishing the weekend as one of five teams on six points.

Napoli also have maximum points after their 2-1 win at Genoa on Sunday, with substitute Andrea Petagna striking six minutes from time to secure the win.

The night was all about Giroud, as he stepped up in the absence of last season's top goalscorer Zlatan Ibrahimovic to inspire his side to victory.

"I am very proud to play for Milan, playing at San Siro is a great emotion," he told DAZN.

"There is something special about being Milan's number nine. I grew up watching (Jean-Pierre) Papin, (Marco) Van Basten and Filippo Inzaghi."

Giroud became the first player to score two or more goals in his first Serie A home match for AC Milan since Mario Balotelli in February 2013.

(Reporting by Peter Hall, editing by Pritha Sarkar)