Needing a win to push for a top-two finish, Oak Flats piled on a massive 8-412 off just 79 overs, with Chatterton making an unbeaten 114.

Chatterton belted nine boundaries and three sixes and was supported by Kieran Gray (79), Nathan Brown (71) and Rob Hill (67).

Third-placed Oak Flats began the round 12 points behind leaders Albion Park, who will need a great batting day on day two just to force a draw.

In other games, Kiama are threatening to wreck Shellharbour's finals hopes after new ball bowler Josh Simpson took 4-39 on debut for Kiama.

After a tight battle last time they met, Shellharbour were rolled for 118 with Kiama struggling at 4-39 in reply before skipper Jye Hartgerink (18 not out) and Jake Ashley (4 not out) stemmed the tide, putting on an unbeaten 23.

Kiama will resume at 4-62, needing another 57 for victory.

The Cavaliers' youngster Mitch Nevins suffered a dislocated shoulder while fielding.

In other games, fourth-placed Kookas are well-placed to claim a vital outright win against Gerringong-Jamberoo after taking first innings points on day one.

Josh Cuthbert took 5-22 and skipper Gerard Healey 3-12 as Kookas rolled the Jets for 75, but the situation could have been much worse as the combined side slumped to 9-31 before a last wicket partnership of 44 between Angus Skorulis (23 not out) and Brian Harris (20) were then bowled out in the final over of the day for 176.

Former Kookas skipper Craig Bramble made an unbeaten 60 on his return to the club.

Finally, Lake Illawarra are poised for an outright win over The Rail, who were bowled out for just 57.

Lakers skipper Shane Cody took 6-11 with Lakers then declaring at 7-148, with Scott Ulcigrai making 47. The Rail are 3-18 in their second dig.