Western Australia 162 and 2 for 139 (Bancroft 79*) need 329 more runs to beat South Australia 7 for 438 dec and 6 for 191 dec (McSweeney 104*, Kelly 3-38)

South Australia remained well placed for a rare win over Sheffield Shield holders Western Australia despite a half-century from Cameron Bancroft keeping alive the visitors' hopes of chasing down a massive victory target at Adelaide Oval.

WA ended the penultimate day at 2 for 139 in pursuit of an unlikely 468 to win. Bancroft was unbeaten on 79 and Hilton Cartwright was also at the crease on 23, with plenty of batting still to come for WA in the form of Aaron Hardie, Josh Inglis and Marcus Stoinis.

WA lost opener Sam Whiteman caught behind off Nathan McAndrew for 17, and the important wicket of veteran Shaun Marsh caught at second slip for 16.

Bolstered by the returning Stoinis and Marsh, WA started the match as warm favourites having already accrued four wins from six matches.

South Australia, in contrast, collected just one win during the first part of the season before the break.

Earlier, South Australia made the most of their 276-run first innings lead to pile on quick runs in search of a declaration.

Nathan McSweeney made it two centuries in as many matches for the Redbacks, hitting 104 not out with 13 boundaries and a six in his 131-ball stint at the crease.

SA resumed at 2 for 31 but McSweeney ensured the home side kept their run-rate high. There were also contributions from Henry Hunt (27), Jake Lehmann (18) and Thomas Kelly (18). Only seamer Matthew Kelly threatened to halt the local sides' charge, taking 3 for 38.