Koonibba are a step away from retaining their Far West football crown after defeating the Blues by 63 points on Saturday to reach the grand final.
A dominant display in the second quarter helped the Roosters to a 19-18 (132) to 10-9 (69) result in the preliminary final.
The Roosters got the jump on their opponent in the early stages as they kicked the opening three goals, before the Blues hit back with two of their own.
There was little to separate the sides in the first term and it ended with Koonibba up by eight points.
They then burst clear of the Blues in the second quarter with four goals inside the opening eight minutes and finished with five goals to one, including two for Jesse Lennon.
The Blues trailed by 38 points at half-time and needed to find a way back into the contest, yet any designs they had on a comeback following David Wright’s third goal of the match to get the quarter started were quickly extinguished by four successive Roosters’ majors.
The Blues did pull two goals back late in the term, however the margin had increased to 46 points.
Koonibba kicked three of the opening four goals of the final term to further extend the lead and saw out the rest of the match to turn their attention to Western United.
Grant Burns and Lawrence Benbolt finished with three goals each for Koonibba, while Thomas Clayton booted five for the Blues.
Koonibba will face the Tigers this weekend in the grand final at Thevenard.
The Roosters also set-up a B grade grand final against Western United with a 15-12 (102) to 4-2 (26) victory over the Blues in the preliminary final.
They were too good for the Blues after half-time to come away with a 76-point triumph.
Waylon Miller led the charge with five goals and was helped by three each from Tyler Mastrosavas and Derek Gray.
Kym Thiele and Michael Pearce kicked the Blues’ goals.
Both sides started two goals in the first quarter to go into the first break level, only for Koonibba to kick clear with three goals to none in the second term.
That put the Roosters 23 points ahead and they added a further six goals in the third quarter to stretch their advantage to 49 points.
The Blues again went scoreless in the final quarter to see Koonibba advance to the decider.
Western United defeated Koonibba in the under 17 preliminary final by 78 points.
The Roosters were never in the contest as Westies secured a 14-9 (93) to 2-3 (15) result.
Koonibba kicked only one goal to half-time to trail by 42 points, with Western United showing their superiority by adding five goals to no score in the third term.
Reefe Fairclough was irresistible in attack and was the only player to grab more than one goal as he finished with five.
Westies will meet Thevenard in Saturday’s grand final.
The Blues got home by just two points in the under 14 preliminary final against Koonibba.
They survived a final quarter comeback to win 3-1 (19) to 2-5 (17).
The Blues kicked the only goal of the first half, then added two more to lead by 16 points at three-quarter time.
While the Blues scoreless in the final term, Koonibba kicked two goals but could not get over the line.
The Blues will meet Western United in the grand final.