Goals from Dinny Corcoran and Dan Byrne helped Owen Heary's side overcome their lower league opponents and advance to the EA Sports Cup last four
The hosts had a player sent off in each half, as Noel Haverty received his marching orders for a deliberate handball in the area and Kevin O'Connor picked up a double booking. Haverty saw red for punching clear a Dinny Corcoran shot, but saw Chris Bennion save the resulting penalty from the striker.
Corcoran made amends with a header just before half-time, but any chance of a Longford comeback was ended when O'Connor received his second yellow card on the hour mark. Bohs looked likely to add to their tally, especially after Steven Beattie came on, but spurned a number of decent chances as they made the most of the extra two men.
The second goal finally came three minutes from time when Byrne added his second to enure victory for Owen Heary's side.
The Gypsies were full value for their win, and now advance to the last four of the EA Sports Cup, while Longford Town return to SSE Airtricity First Division action with a home game agasint Shamrock Rovers B on