Western Australia 0 for 256 (Whiteman 131*, Bancroft 117) trail South Australia 299 (Hunt 71, McSweeney 67, Kelly 5-34, Morris 4-93) by 43 runs

Sam Whiteman and Cameron Bancroft scored unbeaten centuries to put Western Australia in the box seat for their Sheffield Shield clash with South Australia at the WACA Ground.

On a dream day for Western Australia, Lance Morris woke from his slumber as the Warriors team claimed 5 for 21 to dismiss South Australia for 299.

In reply, Whiteman (131*) and Bancroft (117*) put the Redbacks' attack to the sword as Western Australia finished day two at a commanding none for 256.

Whiteman entered the match on the back of a pair of ducks in the recent Shield win over Queensland. But it was a different story for on Saturday as the 30-year-old cashed in to post his tenth first-class century.

Bancroft, who scored 141 in last summer's Shield final, was just as dominant in posting his second ton of the season.

The unbeaten opening stand put Western Australia in prime position to build a big first-innings lead and snare a win that will help them retake top spot from Queensland.

The Redbacks resumed play on day two well placed at 5 for 276, but they lost their last five wickets cheaply to be all out for 299. Paceman Matthew Kelly finished with 5 for 34 off 27 overs to be Western Australia's best bowler, but it was Morris (4-93) who caused the bulk of the destruction on day two.

Morris, who can bowl in excess of 150kmh, returned figures of 1 for 75 off 18 overs on Friday. But he came out breathing fire on Saturday on the way to figures of 3 for 18 during the morning session.

South Australia lost three wickets for no run during a horror start to the day, with Morris the one who sparked the downfall.

Harry Nielsen (38) was the first to fall when his attempt to fend off a fierce Morris bouncer resulted in a catch to a diving Teague Wyllie at short leg. Two balls later Nathan McSweeney (67) fell to Kelly, and Morris continued the destruction with the scalp of Ben Manenti for a duck.

Kelly and Morris claimed one more wicket each to wrap up the innings, before Bancroft and Whiteman took the game away from the Redbacks.