After Nugent broke through and was pulled down the ten men of Luton could no longer contain the home side who are now unbeaten at home in a league match for over 13 months now.
The win means Preston are now only a point behind leaders Cardiff who lost today. More importantly the Welshmen play a tough game at home to Burnley next weekend when Preston travel down to Essex to take on Colchester.
Birmingham look strong in fourth with a gap appearing back to West Brom in fifth position.