"Sometimes when you hit it hard, and I had to hit that one hard, it doesn't fly perfectly straight," said Kasay. "It was dancing a little bit, but by God's grace it went in between the posts."
Kasay made the field goal just as the time clock expired.
DeShaun Foster rushed for 59 yards on 19 carries, making Carolina 22-2 when he has more than 15 carries.
"The way that game went, they had plenty of opportunities to lay down their sword, but they never did," Carolina coach John Fox said. "It was just a great team effort in all three phases."
Saints quarterback Drew Brees completed 29-of-47 passes for 252 yards but also threw two interceptions. "We gave this game away," said Brees. "There is no other way for me to say it. We didn't make the plays that we needed to make."