Leeds United allowed an early advantage to slip to go in level with Nottingham Forest after a frantic 45 minutes at the City Ground.
Green tapped home after 12 minutes following brave work in the penalty area from Luciano Becchio and El-Hadji Diouf.
Forest keeper Lee Camp could only parry Diouf's shot into the path of Green, who made no mistake unmarked at the far post.
Rudolph Austin looked bright for the visitors on his return from injury and smashed over with a strike from distance soon after the opening goal.
Leeds controlled possession in the opening half hour but could not extend their early advantage.
The home side made them pay from the penalty spot two minutes before the break after Tom Lees fouled Billy Sharp in the box.
Sharp made no mistake with a confident penalty to Paddy Kenny's left to bring Forest level at the interval.