South Australia 2 for 164 (Carder 58*) trail Western Australia 9 for 465 dec (S Marsh 118, Green 106, Philippe 77, Cartwright 69, Pope 4-92) by 301 runs
Jake Carder marked his South Australia debut with a half-century against his former team-mates while Travis Head made a steady start to an important personal season as the home side put together a solid response to a hefty Western Australia total.
On a surface that offered precious little to the quicks and only a modicum of gentle turn, Carder and Head took their third wicket stand to 96 by the close to give South Australia a good chance of avoiding the follow-on having been a little unsteady on 2 for 65.
Left-armer Joel Paris had pinned Jake Weatherald lbw and Henry Hunt gloved a pull down the leg side having looked set for a significant score.
Carder, given the No. 3 role after his winter move to Redbacks, was composed throughout while Head, who is probably the frontrunner for the No. 5 spot in the Test team, appeared in good touch although had been a little fortunate when an edge off Cameron Green flew wide of the lone slip.
Green and Lance Morris had some issues with the frontline during their spells with 10 no-balls between them while Morris also twice conceded five wides in a wayward display.
Western Australia had resumed on 4 for 324 after the opening-day centuries from Shaun Marsh and Green. They progressed at a good tempo as the Redbacks' bowlers again struggled to make much of an impression on a docile surface.
Josh Philippe led the way with a half-century off 76 balls which be brought up with consecutive straight sixes in Sam Kerber's first over the day to follow his hundred in the Marsh Cup game. There was a century for the taking here, too, but in his eagerness to keep the innings moving he top-edged Lloyd Pope high to midwicket.
Hilton Cartwright, part of a fifth-wicket stand of 109, took a leaf out of Philippe's book by also reaching his fifty with the first of two back-to-back sixes off Pope and was annoyed when he missed another by picking out deep midwicket shortly before lunch.
Pope, who was barely used by Head on the first day, took his haul to four wickets, the last of them bringing the declaration, although they were all largely donated by Western Australia's push to score quickly.
West Aust vs South Aust
Andrew McGlashan is a deputy editor at ESPNcricinfo