Xavier McDevitt claimed five wickets as Corrimal kept their semi-final hopes alive with a crushing win over Helensburgh at Ziems Park.
The Burgh were routed for 122 after resuming on day two at 0-41, chasing 246.
McDevitt was superb, taking 5-29 off 28.5 overs, including 16 maidens.
Brad Jardine chipped in with 3-22, with the Cougars (41 points) now equal fifth with Helensburgh and just two points behind fourth-placed University with three rounds remaining.
Meanwhile, Matt Gauna narrowly missed out on becoming Wests' first century-maker of the season - caught behind for 99 - in a 28-run loss to Northern Districts at Hollymount Park.
Resuming at 4-36 after Norths declared at 4-241, Gauna and Grant Newman (55) put on a fighting 146 for the fifth wicket.
"It was our best batting day of the season," Wests skipper Dan Bogovac said.
"The top order crashed, but the middle and lower order really toughed it. Matt was unlucky not to get a century and played a great knock and, with Grant, put us right back in the game."
Robert Murphy (4-47) and debutant Curtis Denhartog (3-53) bowled well for Norths.
Port Kembla were in a strong position against Dapto before rain forced an early end at Reed Park.
Port were 2-139, needing another 83 for victory, when play was called off due to a wet patch on the bowler's run-up after a rain delay.
Port opener Daniel Phelps made 33, with Gavin McCauley (60 not out) and Daniel Lee (37 not out) combining for an 80-run stand for the third wicket.
"It was a safety issue and that's fair enough but it was disappointing all the same because I reckon we were heading for a win," Port skipper Matt Skora said.
Leaders Balgownie remain unbeaten and ended the finals hopes of Wollongong with a convincing 62-run victory at North Dalton Park.
Resuming at 1-62 chasing 227, Wollongong were bowled out for 165. Opener Cam Johnson (59) and Andrew Hicks (39) did best while several bowlers contributed for Bally.
Michael Toussis took 3-25, James Fleming 2-28, Shannon Crewdson 2-28 and Dean Merola 2-6.
Keira consolidated second spot with a first innings home win over University.
The Students were dismissed for 111 chasing 158, with NSW Country all-rounder Jono Cook taking 5-27 for Keira.
Chasing outright points, the Lions declared at 2-123 with Mark Johnston making 40. Uni reached 5-109 in their second innings with skipper Mitch Calder (56) top-scoring.
Ladder: Balgownie 70, Keira 58, Dapto 49, University 43, Helensburgh 41, Corrimal 41, Northern Districts 39, Port Kembla 32, Wollongong 29, Wests Illawarra 11.