And the 3-2 win lifts them up to 12th in the Lowland League table on 15 points.
Both sides went into the match at Broadwood Stadium level on points.
After a goalless first half, it was the Colts who went in front through Daniel Hunter.
But two minutes later Russell Currie got the leveller for Gretna. He beat the defender and fired the ball into the bottom corner of the net.
Lewis Turner then put Gretna in front when he latched on to a cut-back cross across the goal and directed the ball into the far corner with his right foot.
And Currie added a third for 2008 when he tapped in from close range to put the Raydale side on course for another victory.
Peter-John McGiff netted for Cumbernauld in the last minute but it wasn’t enough and The Anvils made it five on the bounce.
Last Saturday Gretna beat Tranent Juniors 2-1 at Raydale Park.
The Anvils allowed the opposition to enjoy the bulk of possession, but they managed to strike against the run of play through Calum Helm.
Liam Short then doubled the Gretna advantage in the second half to give the home side a cushioned lead.
Nicky Reid clawed one back for Tranent with a rocket strike past Ally Adams to make it a nail-biting finish, but this was too little too late for the Juniors and Gretna held on to take the three points.
Speaking after the Tranent game, assistant manager Robbie Park said: “It was a great, solid defensive performance from the boys, we are a really strong team defensively and on the offence we’re very dangerous.
“We knew it was going to take a bit of time for them (the players) to gel, but now we’re starting to see the fruits of that.
“We need to keep the momentum and positivity going.”
This Saturday Gretna travel to play East Stirlingshire as they look to maintain winning ways.
