Bale was on hand again just after the hour finding Earnshaw in the box and the Nottingham Forest striker's shot from a tight angle was parried by Eddie Gustafsson.
Forest's fightback started when Adam Hammill fouled Gunter in the box and McGugan slammed in his 10th of the season from the spot and they should have been level soon after, only for Earnshaw to scoop substitute Tyson's cutback over the bar.
It was Forest who created the first chance, with Chris Cohen's cross almost finding Rob Earnshaw in the box only for a defender to nick the chance away from him.