The Redbacks looked steady at 5-223 but lost 3-4 late in the final session on Sunday to finish on 8-262.
A late cameo from Wes Agar (25no off 24 balls) helped the hosts stem the bleeding and ensured they would begin day two at the crease.
"We're pretty happy with that," said NSW quick Jackson Bird.
"It would've been nice to bowl them out before the end of play today but I think we controlled the game pretty well in the middle session."
Veteran quick Chris Tremain (2-40) sparked the collapse with a short ball that bamboozled Harry Nielsen (32) into edging to wicketkeeper Matthew Gilkes.
Only one over later, fellow seasoned campaigner Bird dispatched of Nathan McSweeney.
Slow and steady, McSweeney (64 off 172) had anchored the innings, but things threatened to spill out of control very quickly when Tremain dismissed Ben Manenti only four balls after McSweeney went.
Paceman Agar belted two fours and a six to help South Australia back to their feet.
"We're not too unhappy with it," McSweeney said of the day's play.
"I felt like as a batter it always nipped all day. You never really felt that you were in.
"There's still a little bit of work to do for the second innings but overall, we'll probably take that."
NSW batter Moises Henriques (2-27) broke two solid partnerships with bowling cameos earlier in the day after winning the toss.
He bowled Henry Hunt (26) as he shouldered arms just before lunch, breaking a 46-run stand with Daniel Drew.
Henriques then halted McSweeney's 51-run partnership with Jake Lehmann, whose pull shot flew to Ryan Hackney at square leg.
"Moises bowls so much at training, he's always putting in hard work and still trying to improve at 36," Bird said.
"It was nice to see him get a couple of wickets."
Bird ended with figures of 3-52, with Drew (29) and Kelvin Smith (11) caught behind off his bowling.
Jake Fraser-McGurk was unable to translate his heroics from South Australia's chaotic Marsh Cup clash last Sunday into the red-ball fixture.
In his first knock since belting a record-breaking century from 29 balls, Fraser-McGurk threatened to pick the pace up for the Redbacks with 25 runs from 18 balls.
But he hit first-class debutant Jack Nisbet to Chris Green at point two overs before tea, just as he looked to be getting his eye in.
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