Green's 126 off 194 balls helped lift WA to 8-492 declared, with Josh Inglis (91), Marcus Stoinis (79), Ashton Agar (65) and Joel Paris (49no) also posting significant scores.

In reply, the Redbacks went to stumps on day two in all sorts of trouble at 6-124. Alex Carey is on 20 and Adam Zampa yet to score.

SA's top five batsmen crumbled under the heat of WA's potent pace attack.

All-rounder Stoinis snared the scalps of Henry Hunt (36) and Harry Nielsen (6), while Joel Paris, Matt Kelly and David Moody chipped in with one wicket each.

The Redbacks' day ended in disastrous fashion when Liam Scott was run out from a direct Ashton Agar hit after Carey attempted to pull off a dangerous single.

If WA can roll through SA's lower order on Sunday, it will give them the chance to enforce the follow-on and push for an outright victory.

"It was a really good day for us," Skipper Ashton Turner said.

"It started with the bat and Cam Green finished off what was a brilliant innings with great support from the lower order. Josh Inglis and Ash Agar were brilliant.

"We talk about the first innings setting up games and we've certainly done that.

"And for our bowlers to back the batters up on what is still a good wicket is outstanding."

The Redbacks put in an error-riddled display in the field during WA's innings.

Wicketkeeper Carey dropped two catches, Jake Weatherald grassed an easy catch at gully and the Redbacks fluffed the chance to run out Green when he was on two.

Green went to stumps on day one unbeaten on 95 and he held his nerve early on Saturday to post his second Shield century - less than a month after recording his first.

The 20-year-old was finally dismissed when he was trapped lbw by Adam Zampa.

Day three resumes this morning, with the first ball to be bowled at 10:30am AWST.