The 10-point buffer meant West Coast were constantly struggling to catch up and when Banks added two more penalties early in the second half to take Buller out to 19-6, it looked all over for West Coast.
However, West Coast rallied and threw everything at the home side and, after ten minutes camping on the Buller line only to meet with resolute defence, were rewarded with a try by Rowan O'Gorman. Sean McClure converted and suddenly the visitors were within a converted try of an upset victory.
It was now Buller's turn to apply pressure and it was James Foster who powered through the West Coast defence in an almost copycat manner after a series of Buller drives at the visitors' line.
With only a few minutes remaining Buller seemed safe at 26-13 and so it proved, although the last word went to West Coast with a try to centre Luke Hughes with a few minutes to go. However, it was too little too late and Buller hung on for a 26-18 victory.
The forward battle was an even one with every forward exhausted after a hard physical 80-minute battle. James Foster and Isei Lewaki stood in a totally committed Buller pack while Brad Houston and Rowan O'Gorman were the best of the visiting pack.
In the backs Marty Banks and William Saukuru were outstanding for Buller. The West Coast backs were less inventive on attack although solid on defence with Luke Hughes the pick of them.
Buller 26 (Saukuru, Foster tries; Banks 4 pens, 2 cons)
West Coast 18 (O'Gorman, Hughes tries; Thompson 2 pens, McClure con)
HT: 13-6