England dig in as they chase a record 435 to keep Ashes alive

At tea, England had clawed to 106-2 with Crawley not out 36 and Root on 37 after negotiating the second session for the loss of just Ollie Pope.

England need to win to keep the five-match series alive after being crushed by eight wickets at Perth and Brisbane. Australia, as holders, only need a draw to retain the urn.

With attendance over the first four days swelling to more than 200,000 -- a record for the Adelaide Oval which has been hosting Tests since 1884 -- they face a near-impossible task.

No team has ever chased down more than 316 at the venue, while the biggest successful run chase in Test history was 418 by the West Indies against Australia at St. Johns in 2003.

England took six wickets before lunch to wrap up Australia's second innings for 349 with Travis Head slamming 170 and Alex Carey 72.

It left them with 10 minutes to bat before the break but disaster struck in the second over when Ben Duckett, on four, edged Pat Cummins to Marnus Labuschagne at second slip.

Number three Pope has struggled all series and was widely seen as on his last chance with Jacob Bethell waiting in the wings.

He failed to deliver again, gone for 17 with Labuschagne taking a stunning one-handed catch at full stretch in the slips, again off Cummins.

Watchful opener Crawley took no chances, facing 80 balls as he built a crucial 75-run stand with Root, who needs a big score to save his side.

Australia resumed at 271-4 with Head on 142 and Carey not out 52 and they again feasted early on some mediocre bowling.

Ben Stokes didn't turn over his arm on Friday with assistant coach Jeetan Patel saying he was "knackered" after a stoic 83 with the bat.

The England captain opened the attack on Saturday but Head quickly got to work and reached his 150 off 205 balls with a boundary through backward point, earning a standing ovation from his home fans.

Targeting a maiden Test double-century, Head went on the attack but pulled a short ball from Josh Tongue with Crawley in the deep doing well to get underneath it in glaring sun.

Carey added 20 as he set his sights on back-to-back centuries after an emotional first innings 106.

But he was taken at leg slip by Harry Brook off Stokes, with Josh Inglis (10) following soon after, caught behind by Jamie Smith off Tongue.

With the new ball taken, Brook collected another slip catch to remove Cummins (6), this time off Brydon Carse who then trapped Nathan Lyon lbw next ball.

Scott Boland was the last man to fall, caught and bowled by Jofra Archer with Tongue the best of the attack with 4-70.