Chanceless centuries to openers Daniel Hughes and Nick Larkin have turned the screws on South Australia as NSW seek to continue their head of steam going into the mid-season Sheffield Shield break.
The Blues took control of day two on Saturday and were 0-223 at stumps, trailing the Redbacks by 157 runs.
They will go into day three with Hughes on 105 and Larkin 109 after they brought up their tons within an over of each other in the final half-hour of play.
While the pair were operating on an SCG pitch that offered little sign of life and took few chances after coming to the crease in the first session, they were never troubled by the South Australian attack.
"Hughsy and I have managed to put some runs on the board up the top which is your job when you've got friendly surfaces like this," Larkin said.
"I feel like I've always worked hard and sometimes it's a scratch of luck, sometimes you're just in the zone."
They both brought up their second centuries in three games and have the two highest partnerships for the Shield season - having put on 251 against Queensland last month in Canberra.
The Blues are seeking their third straight win - a remarkable feat given they went winless in their previous 11 clashes.
Coming into the day, the game was in the balance with the Redbacks 5-315.
However a superb spell by Sean Abbott in the morning helped swing the game as the Redbacks were skittled for 380.
Abbott (3-97) started the NSW fightback by snaring danger man Tom Cooper (89) and Nick Winter (0) in successive balls in the second over of the day.
Alex Carey finished on 110 not out after wickets tumbled around him.
After Jake Lehmann and Jake Weatherald's first-day half-centuries, limited-overs Australian keeper Carey was the only Redback to get on with the job.
"It's going to be a big day tomorrow," he said.
"Hopefully we can take some wickets, take some early wickets and then keep the scoreboard under control.
"They would like to bat all day and set us something on day four and we would like to run through them with a reversing ball and a spinning wicket."