Second-half goals from Max Ehmer and Bradley Dack gave Gillingham a hard-fought 2-1 victory over Luton in the second round of the Johnstone's Paint Trophy.
Cameron McGeehan's fifth goal of the season from Dan Potts' deep cross put the visitors in front shortly before half-time.
On-loan midfielder Olly Lee should have doubled the 2008/09 competition winners' advantage two minutes later, but he volleyed at Gills goalkeeper Stuart Nelson from close range.
The Gills, southern section finalists last season who were unbeaten in six League One games at the MEMS Priestfield Stadium this season prior to kick off, drew level in the 65th minute through Ehmer.
The German defender fired home from 12 yards after Town had failed to clear Brennan Dickenson's corner.
And following good work from fellow substitute Bradley Garmston, the Gills' top scorer Dack blazed home their winner seven minutes from time.
Josh McQuoid was then brilliantly denied by Nelson following an incisive Town break, before Potts should have taken the tie to penalties, but the former West Ham trainee sliced wide from 10 yards.