Gallen struck on the hour mark and again on 73 minutes to set up a second-round tie away at Rotherham.
Adam Rundle tested Hatters stopper Shane Gore with two angled drives while Chris Dagnall went close just before the interval when his header was cleared off the line by Kevin Gallen.
Chris O'Grady smashed a shot against the crossbar from 25 yards seconds into the second period while at the opposite end defender Craig Dawson came desperately close to bundling the ball into his own net but recovered to save his blushes.
Dagnall went one on one with Gore, only for the keeper to frustrate Rochdale again and the hosts were dealt a sucker punch in the 59th minute when Craddock's cross to the near post was turned in by Gallen.
The striker netted again 13 minutes later when Kevin Nicholls' corner was headed on target by George Pilkington and Taberner parried only for Gallen to pounce on the loose ball and convert from close range.