Newcastle dominated the first half as the sides went in goalless at the break.
But the hosts finally made their dominance count through a stunning Fabian Schar strike from distance.
Callum Wilson then wrapped up the points with his third opening day goal for the club in a row.
1. Nick Pope - 6
Rarely called into action in the first half aside from a couple of simple catches. Won’t have many easier games.
2. Kieran Trippier - 6
Saw plenty of the ball in the first half but struggled to threaten despite getting into some good areas. Was more composed and solid in the second half. Photo: Stu Forster
3. Fabian Schar - 9
Made an important block in the first half and kept things relatively calm at the back before he stole the show with a fine 25-yard strike to thump Newcastle into the lead.
4. Dan Burn - 8
Made some good blocks to deny Forest the few times they did threaten. Dealt with Johnson’s pace well and dominated in the air. Photo: Mike Hewitt