They worked well together and by the halfway mark had caught and passed the frontrunners to take the race lead. On the final lap, however, Scrimshaw broke a spoke on Western Line.
He was forced out, leaving Bunker, Black and Luff to forge on.
In the sprint to the line at the Brunswick Hall youth trumped experience with Bunker proving too strong for his veteran companions.
Black just out-toughed Luff to finish second both men having ridden strongly throughout.
Visitor Matt Schipper got the nod for fourth, with Mike Wright mustering a good finish for fifth ahead of the hardy Brian Scott.
The only female in the field, Cherie Prince, rode very well to come home in seventh spot.
The scratch riders found their handicap too tough to overcome on the day, particularly after the defection of Duncan Appleton.
Adrian Pettit, crossing eighth just ahead of co-marker Bevan Cheatley, clocked the fastest time.
In the 44km, four-lap B- and C-grade race, club president Stu Bruce scored a good win.
Thirteen riders fronted up at the start although only 10 finished.
Bruce combined well with Pania Hudson in the race lead, then proved too strong at the finish going clear in the final stages for an authoritative victory.
Hudson fought on strongly for second placing ahead of Tamara Ross.
The inexperienced Michaela Walker did well to claim fourth with Alistair Ross fifth.
Scratch rider Megan Blatchford-Peck was sixth, claiming time honours, with her fellow scratch bunch companions Graeme Bull and Alison Richards coming home second and third fastest respectively.
A Grade: Lewis Bunker 1, John Black 2, Alan Luff 3. Fastest time: Adrian Pettit.
B & C Grade: Stu Bruce 1, Pania Hudson 2, Tamara Ross 3. Fastest time: Megan Blatchford-Peck.
