Aussies skipper Steve Smith was one of three Australian wickets to fall in quick succession before lunch in a marked reversal of England's fortunes from their horrendous third day. However, it did not stop Australia from extending their lead to a massive 240 runs as they reached to mammoth total of 662 runs for 9 wickets on the fourth day, with Tim Paine on 41 and Pat Cummins on 36, in reply to England's 403 all out. The home side lead the five-Test series 2-0 and have five sessions remaining to secure the Ashes with by winning the last-ever Test to be played the WACA Ground.
England's hopes of staying alive in the five-match series seemed to be resting with the weather, as rain was forecast to hit Perth later on Sunday afternoon. Smith resumed on 229 runs and added just 10 runs before being adjudged leg before wicket on review after James Anderson's confident shout had been turned down by on-field umpire Chris Gaffaney.
The review ended a chanceless 399-ball epic highest Test innings by Smith, which included 30 fours and one six. The other overnight batsman, Mitchell Marsh, a few minutes earlier had failed to add to his 181 runs when he was trapped leg before wicket by Anderson to end a 301-run partnership with Smith. Australia then had Mitchell Starc run out for one as they lost three wickets for 12 runs, after England had only managed to claim one wicket on the third day. They were lucky not to lose Paine for 11 when he was given out looking plumb lbw to Anderson, only for a review to show the ball would have gone over the leg stump. England in their second innings struggling for 132 runs for 4 wickets.