The second division's top scorers - Kenny Deuchar and James Grady - were among the goals again as Gretna saw off plucky Peterhead.
But the woodwork saved the Borderers blushes twice in an end-to-end first half.
David Bingham fired promotion pace-setters Gretna in front after 16 minutes, rounding off a move he had started on the half-way line.
Grady took a flick on from Bingham and his pass sent Ryan Baldachinno racing down the line to cross low and hard for Bingham to fire home a first-time shot
Peterhead were close to an equaliser when Graeme Sharp met a curling cross from Alan Youngson to head against the Gretna bar.
But they fell further behind in the 29th minute when Baldacchino kept going despite a late tackle by Craig Tully. Referee Allan Muir allowed play to continue, and Deuchar headed home at the near post.
Tully was booked as the teams lined up to kick off again.
A minute before the break Sharp again hit the Gretna bar - this time with a curling left-foot shot.
But Gretna sealed the win in the 71st minute when Peterhead keeper Paul Mathers brilliantly kept out a fizzing Gavin Skelton shot only for Grady to rifle in the rebound.