Orr's curling cross from the right squeezed in at the far post past goalkeeper Joe Murphy.
"I was just trying put it into a dangerous area," Orr told BBC Radio Bristol.
"You see it all the time where the keeper gets caught in two minds whether to come or not.
"Luckily for the team, it has gone over Tamas' [Vasko] head, his run has put the keeper off and it has gone it at the back post. I will take that."