Gymns became the final team to qualify for the Warehouse Fitness Floodlit Cup semi-finals on Sunday.
A goal in each half from Kayleigh Whitehead booked their place at the expense of Colby in a 2-1 win.
The southerners, who only needed a draw to qualify, replied through debutant Sarah Wignall.
Athletics: David Mullarkey in GB squad for European team championships
Island athlete to contest 5,000m race in Madrid later this month
Boxing: Sam Rennie not ruling out further title push this year
Manxman hoping to build on recent WBC title victory
Shooting: Kirkpatrick tops the chart in latest skeet league meeting
League stage winner also enjoys cup success at Meary Veg
Triathlon: Will Draper earns world tour wildcard
Island athlete bound for Vancouver this weekend (13-15 Jun)