Keira claimed top spot in the Illawarra one-day competition and defending champions Dapto charged into the semi-finals following a tense final round on Saturday.
Keira leapfrogged University into top spot and earned a home semi-final on Sunday after a seven-wicket drubbing of Port Kembla.
Port managed only 5-126 from their 50 overs, led by a patient 59 from Daniel Lee, while Nick Bell took 2-11 for Keira.
Lions skipper Graeme Batty (70 not out) then ensured his team claimed the two bonus points to take top spot off Uni.
Keira will host Balgownie in one semi-final on Sunday, while Uni are at home to Dapto in the other semi.
Dapto booked their semi-final place with a bonus-point, four-wicket victory over Wollongong in a day/nighter at North Dalton Park.
Wollongong failed to fire with the bat, managing only 148, with Scott Smith top-scoring with 43 and Dale Scifleet (3-20) and Tommi Bozinovski (3-30) starring for Dapto.
Richard Marsh (36) then led the way for Dapto, who extended their lead in the overall premiership.
Wests Illawarra missed out on the one-day semis after Phil Browning inspired Helensburgh to a six-wicket win at Figtree Oval. Andrew Tougher (65) top-scored for Wests, who posted 7-192 batting first.
Browning followed up his 3-27 with a hard-hitting 94 to lead the Burgh to victory with 5.1 overs remaining.
Wests' defeat allowed Balgownie to make the semis despite a shock three-wicket loss to Northern Districts at Hollymount Park.
On a difficult wicket for batting Bally were bowled out for 124 in the 45th over. Darren Jones (37) top-scored while John Robinson took 3-18.
A rain delay meant the Butchers needed 120 off 48 overs and they reached the target with four overs to spare. Norths were in trouble at 7-99 before Josh Colmer (30 not out) and Eric Denhartog (8no) stood firm in a match-winning 21-run stand.
Corrimal teenager Joseph McDevitt smashed his maiden first-grade century against University at Ziems Park, but the Students won with five overs remaining. The game produced 597 runs, with McDevitt making 105 as Corrimal posted 298. But a century from Kurt Miller (100) guided Uni to a three-wicket win with six overs to spare.
Final one-day ladder: Keira 19, Uni 17, Dapto 16, Bally 16, Wests 15, Norths 13, W'gong 12, Corrimal 11, Helensburgh 9, Port 6.