WA rookie Clint Hinchliffe again inspired the Joondalup victory, providing a strong performance with bat and ball on day one.
The young all-rounder impressed with 3-12 and 40 at Lilac Hill on Saturday.
Midland-Guildford were sent in to bat by Joondalup and were skittled for 134 inside 42 overs.
Aneurin Donald (61no) provided the most resistance, with Ty Hopes (2-31), Brayden Thompson (2-14) and Brett McGlade (2-15) all among the wickets.
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READ NOWJoondalup wasted little time chasing down the target, led by captain Michael Swart’s 48 from 39 balls.
Zac Howard was excellent with six wickets for the Monkey Towners, who bowled out Joondalup for 185 from 42.3 overs.
Midland-Guildford faced one over late in the day, with Hayden Cobley (3no) seeing it out, with his side still behind by 48 runs.