Adebayo Akinfenwa was Northampton's hero as the League One side shocked Bolton in the Carling Cup.
He put the Cobblers ahead from the spot in the 21st minute after referee Graham Laws ruled Gavin McCann had handled.
Akinfenwa added a second six minutes later when he headed Abdul Osman's cross beyond Jussi Jaaskelainen.
Bolton's Gary Cahill was sent off before half-time for a foul on Giles Coke and Kevin Nolan's late strike could not save the Premier League side.
It was a glory night for the much-travelled Akinfenwa, who is now with his 10th club and who played with his head bandaged to protect 12 stitches in a head wound sustained on the opening day of the season against Cheltenham.
Bolton had to battle with ten men after Cahill was sent off, but never looked likely to overcome a side 45 places below them in the league standings.
Akinfenwa almost took advantage of a slip by Bolton debut boy Danny Shittu before he struck twice to put Northampton on the way to victory at The Reebok in a game watched by only 7,136 spectators.
Northampton had nervous moments after Nolan pulled a goal back with eight minutes left, getting in ahead of goalkeeper Mark Bunn to score from close range.
Gary Megson's side thought they had drawn level with a minute to go only for Heidar Helguson's effort to be ruled out for offside and Northampton went on to deservedly seal a place in the third round.
Bolton manager Gary Megson
"We did not defend properly on two occasions and it completely changed the face of the game.
"Akinfenwa is a big, strong lad and at times we did not handle him well enough. At times we got too close to him and I am obviously unhappy about the result."
Bolton: Jaaskelainen, Steinsson, Cahill, Shittu, Samuel (Nolan 64), McCann (Andrew O'Brien 39), Muamba, Joey O'Brien, Mustapha (Davies 64), Helguson, Gardner.
Subs Not Used: Al Habsi, Hunt, Dzemaili, Fojut.
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