The striker struck his second goal of the season after 20 minutes with a delightful lifted finish - silencing Tannadice and ultimately keeping Thistle top of the Scottish Premiership table.
Butcher said of his 24-year-old star: "Billy was great again. I think he deserves to get the chance to show what he can do for Northern Ireland against Russia in their World Cup qualifier in midweek.
"He buzzes around and is always in defenders' faces. He must be a real nuisance to play against."
He added: "I'm very happy with the start we've made to the new season. But that's all it is. We won't be getting carried away. It was a solid all-round display which I was delighted about. We would have won by more but we're happy with the three points."
Terrors boss Jackie McNamara was less impressed, saying: "I think it's important to get the fans behind us whenever we play at home.
"But we were sloppy in a lot of our play and the players need to be brave. That was the most disappointing thing about today's performance.
"They need to take responsibility more because in the times we did that we passed the ball around and caused them problems, But there was not enough of it which was frustrating for everyone."