Cameron White's woes with the bat continued as paceman Chadd Sayers helped South Australia fight back strongly in the second session of their Bupa Sheffield Shield clash against Victoria at the MCG.
White managed just three runs as Victoria collapsed in their second innings to be 8-104 at tea, with Ryan Carters (15) and Jayde Herrick (0) the unbeaten batsmen in charge of building on the hosts lead of 224.
Victoria took 6-19 in a little over an hour in the first session of the day to dismiss South Australia for 100 and had extended their advantage to 176 overall when openers Chris Rogers and Rob Quiney made a bright start to their second innings with an unbeaten 56-run opening partnership.
But then disaster struck for the Bushrangers as SA pace trio Carl Tietjens (2-26), Joe Mennie (2-33) and Sayers (4-24) ripped through the top six Victorian batsmen with ease to leave the game in the balance with two days and one session remaining.
Sayers was the most impressive of the South Australian quicks, with his nagging line and length very similar to what Victorian all-rounder Andrew McDonald used so well in taking 5-21 during the Redbacks' first innings.
Quiney (19) was the first man to go when he flicked a Sayers delivery off his pads in the air and Mennie dived smartly to his right to take a screamer, while Rogers (36) fell just four balls later as the Vics slumped to 2-56.
Aaron Finch didn't look comfortable during his 13-minute stay at the crease and was out for a duck - his second of the match - when Redbacks' skipper Michael Klinger held a regulation chance at first slip off the bowling of Tietjens.
The Redbacks' quicks were getting the ball to move around in the air and it proved too much for White, who was harshly given out lbw after being struck above the roll from a rising Sayers' delivery.
White left the ground shaking his head and pointing at his thigh, but he could do nothing about it as South Australia had taken 4-3 in five overs to work back into the match.
Peter Handscomb joined McDonald at the crease and the duo put on 13, before Sayers had his third courtesy of yet another questionable lbw decision.
Handscomb was hit high on the front pad, but the umpire deemed the ball was going on to hit the stumps and duly raised his finger to reduce the Vics to 5-72.
While there was some doubt about the previous two lbw decisions, McDonald could have no such problems with his when he was caught plumb in front for 10 off Sayers as Victoria fell to 6-77.
That became 7-84 moments later when some smart work from Adam Crosthwaite had Will Sheridan out stumped for 7.
With Sheridan batting out of his crease and shouldering arms to a loose Tietjens' delivery, the Redbacks' keeper threw down the stumps from distance before the Victorian had a chance to get back in his ground.
Carters and Siddle put on a valuable partnership of 18 and looked to be handling the bowlers comfortably, until Siddle feathered one through to Crosthwaite just prior to the tea break to setup an intriguing final session of play.
Earlier, McDonald picked up four of his five scalps and Siddle (3-34) two as South Australia were all out for a meagre total of 100 in reply to Victoria's first innings score of 220.
McDonald and Siddle bowled unchanged during the opening hour of play as the South Australian batsmen failed to cope with a wicket doing a bit in the air.
Tom Stray (29) was the leading run scorer for the Redbacks, while Sayers (12 not out) added what could now be some valuable runs at the bottom of the order.
On the opening day, the Redbacks rolled the Bushrangers for 220, with Mennie snaring 5-42 in an impressive display, while McDonald top scored for the hosts with a well compiled 72.