The Rangers boss was pleased by the youngster’s contribution after he replaced the injured Dean Shiels mid-way through the first half.
And he pointed to rapid improvements in the 17-year-old’s game already despite it being only his fifth top team appearance.
McCoist said: “He was magic today. He’s an intelligent player and there are wee things that I’m more pleased about that maybe aren’t as noticeable.
“His ball retention and decision making and the fact he didn’t switch off at times. I can see improvements in that in the early stages of his career which is great.
“In terms of his decision making he took two players on in the left back position and went past them and then two minutes later put a cross in.
“He got both those decisions right and it’s those things that we were looking for improvements in.
“I thought he was excellent today and so was young Lewis Macleod.”