Western Australia have a 150-run lead over South Australia with three second-innings wickets in hand, following a topsy-turvy Sheffield Shield day with 13 wickets falling in Adelaide.
The Warriors were well placed on Thursday at 1-85 in their second dig only to slip to 7-196 at the close, with no recognised batsmen remaining.
Chadd Sayers was again the chief destroyer for the Redbacks as the Shield's leading wicket-taker followed up his 5-68 on Wednesday with 4-52.
Following a dominant opening day at Gliderol Stadium, South Australia began at 4-156, just 45 runs shy of WA's 201.
However, nightwatchman Sayers was out in the first over and wickets continued to fall at regular intervals.
Warriors paceman Simon Mackin ran through the Redbacks' lower order to take career-best figures of 7-81 in an innings that included two run-outs.
Jake Lehmann added 22 to his overnight total before being the eighth man out for 77, leaving the Redbacks just three runs clear at 8-204.
Only some big hitting from tailender Kane Richardson (33 off 21 balls) extended the lead before Mackin mopped up the tail.
In reply, opener Cameron Bancroft top-scored for WA with a watchful 56 off 150 deliveries, while Hilton Cartwright made 30.
But when Sayers dismissed Cartwright, WA seemed powerless to stop the steady loss of wickets.
