Impressive Gretna continued their fine start to the season with their fourth consecutive away win. Now unbeaten after 10 games, they looked a class above their hosts who tried hard but never looked capable of taking anything from the game.
The visitors dominated from the kick-off and went in front in the eighth minute. A poor back pass from Iain Good fell to James Grady and he finished in style, shooting into the net off the left-hand post from the edge of the penalty area.
Andy Aitken had been booked after 15 minutes when he was carried off with a knee injury after landing awkwardly seven minutes later.
Peterhead's David Hagen ensured the stretcher bearers had a busy afternoon when he had to be replaced two minutes into the second half after pulling a hamstring running down the left wing.
Peterhead's only two chances of note fell to Martin Wood, and a more clear-cut one to Hagan's replacement Graeme Sharp.
But Gretna finished the game with a simple second goal on the hour. Ryan Baldacchino sent over a pin-point corner kick from the left, and defender Chris Innes rose unchallenged to head into the right side of the goal from the edge of the six-yard box.