Manager Paul G Stephen opted to change a winning system despite three triumphs on the trot in preseason for his Cubs, deploying centre-half warrior Callum Ross in a lone forward role, with strike stalwarts Adam Jamieson-Caley and Jack Brebner relegated to the bench.
The physicality of Ross made an immediate impact, with DUSA forced onto the back foot as the targetman made a nuisance of himself.
Ross should have had the ball in the back of the net when he tumbled under the challenge of a Pirate defender in the box, only to see his poor penalty parried and the rebound effort drift wide.
In truth Cubs should have opened the scoring on several occasions before they did, with Martin "Yug" Mackay guilty of a trio of misses after good work down the right flank.
The goal when it came was from the opposite wing, as Robbie Small drove across the box and beat the keeper with an angled drive.
It was two not long after, as Small raced clear again before releasing the restored Brebner, who cut into the area and arrowed the ball into the far corner of the net to send a message to his manager.
Again the Cubs could and perhaps should have punished the Pirates further, with veteran utility man Phil Sim blazing over with what for him was a routine wrong-footed bicycle kick at the back stick from a Michael Sword free kick.
The visitors had failed to settle into the game, as they were outnumbered and outfought in a midfield battle in which Jamie Baird excelled once again.
DUSA were often forced into lofting the ball long, efforts which were easily mopped up by Sword and the imperious Calum MacDonald, who didn't lose a header all day. Such was the dominance of the home side, at the half Cubs custodian Harry Eggo professed to have been bored by the lack of action he faced in the opening period.
Into the second half and the Cubs continued to make their advantage count, with Brebner notching his second with a cool finish in a one on one, and DUSA's misery was complete when Stephen's header back across the box was directed into the net by a luckless defender.
Jamieson-Caley resumed his familiar position on the scoresheet, nodding a Cruickshank cross past the keeper, before Mackay finally got his goal, sliding in at the back post to tap home another Cruickshank delivery.
There was time for DUSA to grab a late consolation goal, as the Cubs defence failed to deal with a bouncing ball, leaving the forward irritatingly wearing number 2 free to nod the ball over the onrushing Eggo and into the net.
When the final whistle sounded the Cubs had completed a routine win in a traditionally tricky tie. What will particularly please manager Stephen was the way his players maintained discipline and kept up their possession-based system regardless of personnel, as a flurry of substitutions threatened to break up the tempo of the game.
