Australia have posted their highest total in a home Ashes test innings, declaring with a first-innings lead of 259 runs shortly after lunch on day four of the WACA clash.
Steve Smith puts the England bowlers to the sword. Photo: Photosport
Steve Smith called his teammates in at 9-662, three and a half overs after Sunday's meal break.
Smith and Mitch Marsh were unable to extend their game-changing partnership of 301 runs.
But Tim Paine and Pat Cummins further demoralised England in 93-run stand.
Root set defensive fields and opted against taking the third new ball, waiting for Smith to declare.
Stuart Broad finished with figures of 0-142 from 35 overs, the worst of his test career.
Marsh failed to add to his overnight score of 181, falling to the second ball of the day when he was trapped lbw by Jimmy Anderson.
Smith's career-best knock ended on 239 when he was also pinned lbw during Anderson's opening spell on Sunday. The skipper was initially judged not out but counterpart Root successfully reviewed.
Smith achieved the third highest score by an Australian captain in an Ashes test, having faced a staggering 399 deliveries as he pushed for an unassailable 3-0 lead in the five-match series.
Mitchell Starc was run out after a terrible mix-up with Paine but the keeper steadied after a collapse of 3-12.
Paine could have been found short of his ground on one after a miscommunication with Cummins, while he successfully reviewed an lbw dismissal on 11.
Mother Nature, not mother country, looms as the biggest threat to Australia capturing the urn in Perth.
A thunderstorm is expected to disrupt play on Sunday afternoon, while more rain is predicted on Monday's final day of play.
Australia coach Darren Lehmann admitted prior to the start of play on Sunday the weather would be a factor in any declaration.
"You sort of think about that a little bit," Lehmann said.
England paceman Craig Overton, who has a cracked rib, left the field after diving to stop a ball in the deep.
- AAP
