Keir led after round one of the contest but could not hold off fellow State Team members Hanna Green (Mt Lawley).
After the first round, Green was one shot off the pace, shooting a five-over par 77, to sit one shot behind Keir and a shot ahead of Hira Naveed (Mt Lawley).
Green raced ahead of the pack early in round two, opening the first three holes with two birdies and an eagle. Finishing the day with an impressive three-under par 69, Green secured the championship by six shots at two-over par, with Keir six shots back at eight-over and Naveed in third at 13 over.
While Green cruised to victory, Minwoo Lee’s (Royal Fremantle) victory in the Junior Boys’ Championship was quite unexpected.
Curtis Luck was the only golfer to easily handle the difficult course layout in the first round, shooting a two-under par 68 to hold a commanding six-shot lead.
However, his faltered late in his second round. Beside the green in two shots on the final hole, Luck chipped within a few meters but three putted from there, a testament to the very fast and difficult greens on the course throughout the event.
The double bogey handed Lee the outright victory by a single shot. He shot a final round 73, to finish plus-8 for the event.
The WA Championship is one of only two local junior events which count towards the Golf Australia National Junior Rankings.
Previous winners include Craig Parry, Tanya Holl, Jarrod Moseley, Scott Strange and Kristie Smith.