Meanwhile, Oak Flats beat Kookas in a semi-final eliminator and Albion Park clinched the minor premiership on a remarkable last day of the regular season.

Shellharbour scored 10 runs off the final over of the contest to claim an outright win over Gerringong-Jamberoo, leapfrogging the beaten, third-placed Kookas into the semi-finals.

A late-afternoon storm which washed out the rest of the round missed Gerry Emery Oval.

This left Shellharbour needing 86 off 12 overs for an outright result.

They scored the necessary runs with two balls to spare.

It took just a handful of overs on day two for Oak Flats to seal their finals place, leaving the Kookas nervously hoping Gerringong-Jamberoo could avoid outright defeat against Shellharbour.

Kookas began day two at Oakleigh Park on 6-79 chasing 125 for victory, but were quickly bowled out for 85.

Andy Twyford started the day's play with 5-8 for the Rats, snaring two more wickets to finish with a season-best 7-10.

In other games, Albion Park took out the minor premiership with a gritty first innings victory over Lake Illawarra at Keith Grey Oval, and Kiama Cavaliers handed The Rail the wooden spoon after a comfortable win.

Albion Park take on Shellharbour at Keith Grey Oval in their semi-final this weekend, while the Lakers host Oak Flats at Howard Fowles Oval in the other playoff match-up.