Defending 185, Kwinana were looking good at 2-124 before a middle order collapse, ending in a thrilling win for the home side by just three runs.
Dylan Allsopp was the best of the bowlers with 4/30 and Tom Bray took 3/35.
Fourth grade went down to Kwinana at Orelia Park, bowled out for 155 chasing 215 for victory.
Trent Cremin top scored for the Crows with 55.
Sixth grade had a closely fought match with Leeming Spartan at Centenary losing by just six runs on the first innings, with 115 to 121.
Michael Dentrinos took 5-31 and the Crows were bowled out for 29 in their second innings.
Leeming chased down the total of 23 points in two overs, finishing at 0/24.
The One Day Ds had a convincing win over Riverton-Rostrata at Riverton Primary school, restricting the home side to 7/140 with Leon Groenewald taking 3/29.
A partnership of 197 between Kris Johnson (95) and Chad Forsyth (135) was the highlight of a Crows total of 6/282.
The One Day Fs lost to Cockburn at South Coogee Reserve, making 191 batting first, before Cockburn responded with a total of 239.