Prater fired a 64-yard effort through the posts at Sports Authority Field breaking the record set by Tom Dempsey, Sebastian Janikowski and David Akers of 63 yards in the Broncos' win over the Tennessee Titans.
"I was clueless," Prater told the Denver Post. "I didn't know he was going to call for the field goal. I didn't know the kick would be from where it was.
"I think it helped me to get out there late. Because I had to rush out there, I didn't have much time to think about it."
Prater has kicked 18 of the 19 field goals he has attempted this season at a success rate of 94.7%.