Gavin Reilly was the star of the show with a second half hat-trick to add to his goal in midweek against the SPL side.
Willie Gibson opened the scoring on 17 minutes with a 25-yard shot and Nicky Clark made it two when he picked up on a poor passback by Alex Keddie to shoot home.
Arbroath missed the chance to gain a foothold before half-time when Steven Doris rattled a penalty off the woodwork.
Reilly headed in his first on 52 minutes, before adding a second with a volley just after the hour. Substitute Kevin Smith made it five and Reilly completed his trio with a last-minute strike from 12 yards.
Dumfries player/manager Allan Johnston said: “We created lots of chances and it was good to see the goals going in. Gavin missed a chance early on but he did not let that affect him.”
Gayfield boss Paul Sheerin groaned: “We have not been firing on all cylinders this season but we made that worse by giving away goals through bad mistakes.”
Stenhousemuir were turned over 4-0 by promotion dark horses Forfar at Ochilview. Stephen Tulloch and Iain Campbell, from the penalty spot, had the Loons ahead before half-time with Danny Denholm and Chris Templeman both scoring in the second period to move Forfar into second place.
Alloa fell behind to an Andy Jackson goal for Brechin on 51 minutes. However, they rallied and ran out 3-1 winners with Robert Thomson, Kevin Cawley and Martin Grehan all netting.
Albion Rovers scored their first goal of the season and got their first win when they saw off hosts East Fife 2-1. Scott McBride opened the scoring within a minute but debutant Jordan Forster was unfortunate to turn the ball into his own goal to level just before half time.
Kieran Brannan netted the winner to move Rovers into eighth place with Ayr United now propping the table up after Craig Malcolm grabbed a brace for Stranraer in their 2-0 win.