A man-of-the-match performance from captain James King has seen Wests claim a second Tom Locker Cup final in the space of four seasons.
King scored 125 as the Rosellas made a run-a-ball total of 4-241 at home at Harker Oval on Sunday before dismissing the two-time defending one-day champions for 203.
King's 113-minute knock, featuring 12 fours and five sixes, was made from 105 balls.
Wests won their first Tom Locker Cup title in 2017-18. That same season King was also named player of the two-day final.
Batting at No.3, King shared partnerships of 79 with Ben Chew (44) and 90 with Aaron Wivell (23) during the middle overs of the innings.
Hamwicks had won the toss and elected to bowl.
In reply, Rhys Hanlon was the mainstay for the Pumas with 84.
Rosellas opening bowler Brad Aldous recorded figures of 3-35.
