The hosts recovered from a pair of perilous positions to post a solid score at stumps
Match Report:
ScorecardCooper leads Redbacks revival on see-sawing day
Half-centuries from Tom Cooper and Harry Nielsen helped South Australia revive and reach a competitive position at Adelaide Oval as the Marsh Sheffield Shield season resumed following a two-month hiatus.
South Australia ended day one at 8-352, having recovered from 2-25 and 5-143 after being sent in to bat.
Cooper led the way but the veteran missed out on his 14th first class century after being bowled by Joel Paris on 99.
"It is and it isn't (frustrating to be dismissed for 99) – it's just a number," Cooper said after play.
"Obviously you don't get the dash in the stats column, but if I'd got told I'd get that at the start of the day you'd take it most times.
"So while it's frustrating, it's got us in a really good position so I won't be losing too much sleep.
"After losing the toss this morning, we're very happy with where we sit at the end of the day's play.
"The ball swung all day which is what the Dukes does.
"That's what we expected, but the pitch was a little bit slow so it was hard to hit through the line."
Along with wicketkeeper Nielsen (53), Cooper helped SA counter-punch with a 80-run stand for the sixth wicket.
The tail also added invaluable runs late on with Chadd Sayers ending on 38 not out and Daniel Worrall unbeaten on 19.
Earlier, Jake Weatherald scored a composed 60, while Test batsman Travis Head compiled a confident 46, including seven fours.
Western Australia's seamers enjoyed plenty of dividends for the first half of the day with the Dukes ball, which was introduced for the second part of the Shield season.
Paris and David Moody both returned 3-70, while wicketkeeper Josh Inglis claimed three catches, as did Shaun Marsh at second slip.
With just one victory from six outings, the Redbacks need to win the match if they are to stay in touch with second-placed WA and remain in the hunt for a berth in next month's final.
"We were discussing 260 at the start of the day, so we're very happy at the moment," Cooper said.
"But you never know until both teams have batted so we'll wait and see.
"We'll go out there and try and get a few quick runs in the morning, and then hopefully our bowlers can get a couple early and turn it into a really good score."
South Australia XI: Henry Hunt, Jake Weatherald, Callum Ferguson, Travis Head (c), Tom Cooper, Will Bosisto, Henry Nielsen (wk), Nick Winter, Chadd Sayers, Daniel Worrall, Wes Agar
Western Australia XI: Cameron Bancroft, Jake Carder, Shaun Marsh (c), Marcus Stoinis, Cameron Green, Josh Philippe, Josh Inglis (wk), Joel Paris, Matthew Kelly, Liam Guthrie, David Moody