After the high drama of their cup victory over St Mirren ten days ago, it was back to the bread and butter of the league in front of just 598 spectators.
And it took a while for Gretna to click, with James Grady putting them in front midway through the first half and two goals coming soon after half-time.
Steve Tosh limped off in the 12th minute to be replaced by Ryan Baldacchino and the sub set up Grady's opener.
David Nicholls sent him racing to the by-line and Grady met his cross with a downward header that bounced up and in.
Dumbarton defended in depth relying on quick breaks, but went close when a Chris Boyle free-kick flew across the home side's goal needing just a finishing touch.
Six minutes into the second half Gretna doubled their lead. Grady played Kenny Deuchar in and the big striker rounded Dumbarton keeper Stephen Grindlay and shot from a tight angle.
Dumbarton defender James Smith got a foot to the ball, but it rebounded off the post for Ryan McGuffie to apply the finishing touch.
And Grady set up Gretna's third after 63 minutes with a far-post cross from the by-line for the unmarked Deuchar to head home.