A change of approach at half-time was the reason for AC Milan's impressive 2-0 win over Roma at the Stadio Olimpico, according to head coach Gennaro Gattuso.

Milan rarely threatened during a tepid first-half but came out for the second period rejuvenated and took the lead after 48 minutes thanks to Patrick Cutrone's sixth Serie A goal of the season on Sunday.

Davide Calabria's first ever goal for the club doubled their advantage 16 minutes from time as Milan extended their unbeaten run in Serie A to eight games and 12 across all competitions.

Gattuso admitted that his side struggled in the opening 45 minutes and was keen to try a different approach after the interval.

"It was a hard-fought game, we suffered a lot in the first half and tried to play different football in the second half, seeking different passing lines," he said.

"We played too many balls down predictable lines in the first half and I didn’t like that. I prefer to go down the wings and bring the full-backs into it. Franck Kessie contributed to the goal for Calabria, as he went in there and helped create the space.

"We like to bring men into the box with movements, both on and off the ball. I also want to stop for a moment and praise the defence, because we always move at the right moment and are united. I am very happy about that.

"I think Roma are a fine team and we had to fight really hard for this."

Roma boss Eusebio Di Francesco was left to rue his side's first-half wastefulness and said he was alarmed by their display in the second period.

"I thought we had a good first half and allowed Milan very little," he said.

"We weren’t determined enough in our finishing, that is true.

"However, after the opening goal, we lost our way. That is something that must make us think and think hard. It was not a physical issue, we simply lost control of the game.

"Obviously it's an alarm bell. We cannot be happy with this result, nor our season overall. We expected a different performance in the second half. We lost our unity and I was surprised by that.

"Milan did very little in the first half, whereas we created dangerous situations, but without the belief to finish them off."