The side, under the stewardship of player-manager John Cotter, travelled to Station Road in St Johnston with just 12 players but still had far too much for their Ulster Senior League opponents.
Former Cork City striker Mark O’Sullivan scored twice, while Conor Meade was also on the mark. Cormac Carlin curled home a well-taken free-kick for the hosts but it was merely consolation.
O’Sullivan snuck in behind Dermot Kelly following a pass from Meade and coming in from the right flank scuffed the opening goal past Marty McGinty in the ninth minute.
Meade made sure of the away win eight minutes into the second half when he rose unchallenged to head home a tempting cross from O’Sullivan.
Then, on 69 minutes, O’Sullivan had the freedom of east Donegal as he had all the time in the world to pick his spot for number three.
Kildrum got a goal back 14 minutes from time when Carlin scored a fine free-kick, awarded after Avondale keeper O’Leary was penalised for handling outside the area.
KILDRUM TIGERS: M McGinty; J McGinty, D Kelly, R McGarvey, D Cassidy; G Crossan (D Doran 58), D McCready, G Bovaird (D Crossan 72), O McMenamin; G Doherty (R Coyle 66), C Carlin.
AVONDALE UNITED: D O’Leary; D Spratt, M Mulcahy, G McCarthy, D Cahill; E Lougheed, H Donovan, B Murphy, M O’Sullivan; C Meade, D Long.
Referee: T Moyne.