NSW opener Daniel Hughes has posted his highest first class score with the Sheffield Shield leaders setting South Australia a near-impossible task at Bankstown Oval.
The hosts scored with ease to reach 2-236 before declaring during the final session with a lead of 402.
SA openers Jake Weatherald and Henry Hunt looked set to survive the 17 overs before stumps, only for the latter to fall off the bowling of Liam Hatcher in the dying stages for 15.
Weatherald ended the day unbeaten on 19 with SA at 1-40. A win for NSW would all but lock up their spot in next month's final with two rounds to be played.
Hughes followed his first innings 103 with a confident knock of 136 from just 170 deliveries, including 22 boundaries, surpassing 3000 first class runs along the way.
Hughes' seventh first class century came off 141 balls and he had just surpassed his previous best of 134 when caught on the boundary off the bowling of Chadd Sayers.
Along with Nick Larkin (32), Hughes helped add 94 for the first wicket.
Rookie Daniel Solway continued his impressive debut season with an unbeaten 53 off 69 balls on his club home ground.
Batting wasn't so easy for South Australia's tail-enders during the morning session with Trent Copeland leading the Blues' attack.
Copeland added two more scalps to his overnight haul to end with 5-63, surpassing the 300-wicket mark for NSW in the process.
South Australia resumed at their overnight 6-135 but were eventually dismissed for 207, leaving a deficit of 166 on the first innings.
Defeat for fourth-placed SA would mean they need to rely on other results to keep their Shield campaign alive.