After a goalless first half, the on-loan Aston Villa midfielder opened his Lilywhites account just before the hour mark.
Paul Gallagher then added a second 18 minutes from time to cement North End’s position in the League One play-off places.
Scunthorpe almost took the lead after just 10 minutes but Liam O’Neil lofted a 30-yard effort inches wide of an open goal after Preston keeper Sam Johnstone’s poor kick.
Johnstone then flapped at a corner shortly after half-time but Paddy Madden’s shot from 12 yards was cleared off the line by Gallagher.
Preston took the lead in the 58th minute when Callum Robinson pulled the ball back from the left and Johnson swept home from six yards.
Simon Grayson’s side, who have now won three league games in a row, wrapped up the win after 72 minutes when Chris Humphrey squared for Gallagher to finish from close range.