The 36-year-old netted a brace as United thrashed Newcastle 4-1 on Saturday.
Bruno Fernandes and Jesse Lingard also got on the scoresheet at Old Trafford.
Ronaldo was delighted with his goals and the three points, stating he was happy to help the team.
He said: “My return to Old Trafford was just a brief reminder of why this stadium is known as the Theater of Dreams. For me, it has always been a magical place where you can achieve everything you set your mind into.
“Along with all my teammates and with the amazing support that we always get from the stands, we face the road ahead with confidence and optimism that we’ll all be celebrating together in the end.
“Proud to be back at Man. United and playing in the Premier League once again, but above all, happy to help the team!
“Let’s go, Devils!”