First-class debutant Blake Nikitaras has impressed for NSW as they look to end their Sheffield Shield campaign with a win over South Australia on Saturday.

The match has become a dead rubber with Western Australia and Victoria now locked in for next week's Shield final in Perth, but NSW can still take plenty of positives from the match in Adelaide.

The Blues went to stumps on day three at Karen Rolton Oval at 4 for 235, holding a lead of 252 after three batsmen made half-centuries.

The day was highlighted by Nikitaras, with the 21-year-old making 56 to go with the 44 he posted in his first innings, looking brilliant throughout and belting two huge sixes.

He looked set to push for triple figures until a disastrous mix-up with Matthew Gilkes that saw both stranded mid-pitch, with a direct hit from Brendan Doggett running him out.

Fresh from 142 in the first innings, skipper Jason Sangha remained in imperious touch and brought up another half-century, eventually caught off Nathan McSweeney for 62.

And Gilkes was also in fine form, making his fifth first-class fifty before he fell when McSweeney trapped him lbw for 54. Lachie Hearne could yet be a fourth Blue to raise the bat, 31 not out at stumps. McSweeney (2-71)was the pick of the SA bowlers.

South Australia declared 17 runs behind NSW at 9 for 277 late in Friday's morning session after NSW dismissed captain Henry Hunt (109) and Harry Nielsen (63) early with tail-ender Liam Scott whacking 30. Chris Tremain (3-51) and Trent Copeland (3-58) were NSW's best bowlers.