Backs Jonathan Davies and Alex Cuthbert might have scored the tries in a 26-9 victory, but the pack - and front-row in particular - built an imposing platform.
"Our scrum was outstanding," said Roberts, after Wales weathered torrential rain and testing conditions to post four successive Six Nations away wins for the first time. "Adam (Jones) was magnificent, as were Gethin (Jenkins) and 'Hibbs' (Richard Hibbard). I take my hat off to the forwards - they worked so hard."
He went on: "Tight games are often decided by things like a bounce of the ball, but we got our just reward.
"Defensively we were strong as well. The communication was good. We've been doing a lot of hard work with (defence coach) Shaun Edwards, and not to concede a try away to Italy is an achievement."
Wales head to Murrayfield next on March 9 for an appointment with Scotland, followed by what could be a title showdown when Grand Slam-chasing England arrive in Cardiff seven days later.
In the short-term, Wales will need to monitor Jenkins' fitness after he suffered a calf muscle injury that could make him a doubt for Edinburgh. But if the 97 times-capped loosehead were to be ruled out, Wales have an able deputy in Bath's Paul James, who again provided quality bench cover in Rome.
"It was a very pleasing win," Roberts added. "We wanted to play rugby, but we had to adapt our game because of the weather.
"We had to play 10-man rugby with the backs chasing the ball, but it was great to win and it sets us up to face a much-improved Scotland side at Murrayfield in a couple of weeks.
"We would like to have played an expansive game, but we couldn't in those conditions, and I thought we adapted our game well and fronted-up well."
- Sports & Recreation