Claremont scored three goals in the first 14 minutes of the final term, but Swan Districts had done enough and then Emily McGuire confirmed the victory with her second goal shortly before the final siren.
By the main break Mundaring had opened up a commanding lead and although the Lions were getting their hands on the ball they made many errors due to the pressure they were under.
The Midland Guildford skipper struck consecutive centuries against Tasmania’s second XI in February before making his One-Day Cup debut against the Tigers.
The Eagles were able to kick six goals in just over 20 minutes and threatened to take the lead getting to within two points on two separate occasions before three quarter-time.
The Ellenbrook Easterns started in the field with the home team advantage and went straight to work like they had all season but there were times the Jaguars had them under pressure.
It's been a great year for the senior female sides at Midland Guildford who, after also winning the A grade T20 premiership, won three of the four premierships available to them.