Shellharbour are poised to snatch a semi-finals spot while the season is on the line for Kookas and Oak Flats in a tense day in South Coast cricket.

Fifth-placed Shellharbour will grab a top-four spot if they can beat Gerringong-Jamberoo outright and are well-placed heading into Saturday's second day's play, having already collected first innings points.

Shellharbour dismissed the Jets for 108 and resume play on Saturday at 5-127.

Brynley Richards took 3-8 and made 37 for Shellharbour, while skipper Ben Mitchell took 3-42 and is unbeaten on 24.

"We know an outright win puts us in the finals and that's what we're aiming for," Mitchell said.

Shellharbour's charge for outright points is bad news for third-placed Kookas or fourth-placed Oak Flats; the loser of their clash is set to miss the finals.

Oak Flats won the Twenty20 crown last Sunday and both clubs believe they can win after an even first day.

Nathan Brown played a lone hand with the bat for Oak Flats as he accounted for 80 out of the Rats' 124.

Scott Cox (5-25) and skipper Gerard Healey (3-15) dominated with the ball for Kookas but they resume at 6-79 - needing another 46 for victory. Mick Perry is unbeaten on 33.

Meanwhile, Albion Park are on the box seat to claim the minor premiership after they took first innings points from Lake Illawarra, who headed into the final round as leaders.

The Park dismissed the strong Lakers batting for just 102 - Kerrod White made 64 - and finished the first day at 8-140.

Rob Monaghan took 4-34 for the Park, while Park skipper Adam Coughlan made 47 and Graeme Smith was unbeaten on 50.

Lakers skipper Shane Cody believes his team can win the match and claim the minor premiership.

Finally, The Rail resume at 2-30 as they chase 156 for victory over Kiama at Croome Cricket Oval.

Nathan Barr (44) top scored for Kiama, who were 1-103 at one stage, while Joel Willstrop (3-45) and Jarrod Colliss (3-23) bowled The Rail back into the contest.

Premiership ladder

(before final round):

Lake Illawarra 157, Albion Park 150, Kookas 144, Oak Flats 138, Shellharbour 126, Kiama 82, Gerringong-Jamberoo 63, The Rail 61.