South Australia 8 for 482 dec and 3 for 93 lead New South Wales 7 for 366 (Patterson 102, Abbott 71, Nevill 62, Starc 54*) dec by 209 runs
Mitchell Starc briefly threatened to burst the game open in Adelaide after New South Wales had declared behind in a game dominated by batsmen, but South Australia recovered to extend their advantage to 209.
The Redbacks are in a similar position to the previous round where they will need to judge a target to set on the final day - last week they were one wicket short of victory at the WACA - although the late loss of Travis Head, edging Nathan Lyon to slip, kept New South Wales in with a chance of bowling them out.
After starting their second innings with a lead of 116 they lost two early wickets as Starc, who earlier scored an unbeaten half-century, recaptured the late swing that he has struggled to find consistently this season in the first-class game. He shaped deliveries into the pads of Henry Hunt and Liam Scott to win lbw appeals which left South Australia 2 for 1 in the fourth over.
The in-form Head responded aggressively, getting off the mark with a cut over point for six off Starc, and added 77 for the third wicket with Jake Weatherald before a lovely delivery from Lyon found the edge late in the day and was neatly held by David Warner.
South Australia had visions of bowling New South Wales out to gain a significant lead when they had them 6 for 259. Kurtis Patterson reached his century before becoming the first first-class wicket for left-arm wristspinner Joe Medew-Ewen when he drove a catch to short cover.
Peter Nevill's half-century was ended when he edged the new ball to second slip straight after lunch before any hope the home side had of rattling through the lower order was halted by Starc and Sean Abbott as the pair added 80 for the seventh wicket following their partnership of 189 against Tasmania earlier in the season. South Australia have still to bowl a side out in this year's competition.