Australia have left England facing an uphill battle to save The Ashes after an unbeaten partnership of 301 between Steven Smith and Mitchell Marsh gave the hosts control of the third Test in Perth.
England went into day three with a 200-run advantage, although the feeling was that Smith had to be removed during the early stages if the Baggy Greens were not going to turn 203-3 into a sizeable lead.
However, while Moeen Ali struck to take Shaun Marsh's wicket for 28 at 248-4, Smith and Mitchell Marsh would dominate the rest of the day and leave England staring defeat in the face with a 146-lead having been established with Australia on 549-4.
Smith was untroubled in bringing up another double-ton for his country and he ended the day on 229, while Marsh turned his maiden century into a knock of 181 off just 234 balls.
An early declaration on Sunday appears inevitable - once Marsh has reached his double century and Smith has progressed to 250 - but England face the prospect of having to bat out at least five sessions in order to avoid going 3-0 behind - and losing The Ashes - before the Boxing Day Test in Melbourne.
