Travis Head has reached a half-century, the first by an Australian in this match, but is only delaying the inevitable at Perth Stadium.

Steve Smith lost his wicket for 17, edging behind a Mohammed Siraj delivery late in the first session of day four, and has now gone 23 innings without a century — the longest drought of his career.

Head had looked easily the most comfortable Australian at the crease at any point in this Test. He has driven well and played typically smartly behind square, bringing up the milestone by flicking a ball from Siraj over the wicket-keeper’s head for four.

He is on 63 and hometown hero Mitch Marsh is five, but Australia are 5-104 and still require 429 to complete a record chase.

There are question marks around Marsh early in the series, after a lacklustre contribution with the ball on day three and some concerns over his fitness.

Word out of the Australian camp was that Smith, who has returned to the No.4 position this summer after a short-lived experiment at the top of the order, had “found his hands” and was hitting the ball well before the series.

But he copped a Jasprit Bumrah ripsnorter in the first innings and was out for a golden duck.

Usman Khawaja departed in the first 10 minutes of the day after a late pull-shot shot up for Rishabh Pant to take running backwards for four.

Head survived a wild appeal for lbw from Mohammed Siraj where he ran past the stumps in celebration, only for a review to show the ball was missing the stumps.

And Smith copped a ball from Harshit Rana in the lower rib cage. The former Australian skipper appeared winded and lay on his back before he was treated by the physios and continued on.