Montrose looked good in the opening exchanges and they shocked the League leaders when they opened the scoring after 17 minutes.
Graeme Sharp fastened on to a header from Kerr Dodds and supplied a fine finish when he drilled the ball low past David Mathieson.
Gretna equalised just two minutes later when a cross from Gavin Skelton was deflected on to the head of Kenny Deuchar and he nodded home from close range.
Gretna went 2-1 up in the 24th minute when a cross by Ryan Baldacchino found Deuchar and again he headed powerfully home.
Montrose battled back and levelled the scores in the 31st minute when Euen Hall collected a cross from Paul Doyle and shot first-time into the bottom corner of the net.
Just a minute later Gretna got themselves back in front. A cross from Baldacchino took a cruel deflection off Alan Budd and crossed the line for an own goal.
Gretna looked to make the points secure early in the second half and Deuchar just missed the target with a looping header, then Ryan McGuffie hooked a shot over.
In the 62nd minute home keeper Jim Butter saved well at the feet of David Bingham, then substitute Derek Townsley drove over from a tight angle.
A chip from Bingham landed on the roof of the Montrose net before Deuchar was denied his hat-trick by another fine stop from Butter.
Montrose rallied and Doyle headed just wide from a Kevin Webster corner, then Calum Watson just failed to connect with a Webster cross in front of goal.
Butter kept Montrose's hopes alive five minutes from time with another fine save from Skelton.
In the final minute Montrose had one last attempt at salvaging a point when Watson broke on the left and had a low drive saved by keeper Mathieson.