A similar triumph eluded Shaun Marsh in the last over on Saturday but a second hundred of the Ashes series will be there for the taking on the fourth morning when he resumes alongside younger brother Mitchell.

The Marshes made the Test stage their own backyard like never before in adding to England's discomfort, enjoying their highest stand together for Australia.

Both remain unbeaten, Shaun on 98 and Mitchell on 63, and intent on grinding the tourists into the dust on Sunday when the temperature is forecast to soar towards 40 degrees.

Shaun seemed destined to raise his bat before stumps on the third afternoon as he edged towards three figures, taking a single from the first ball of James Anderson's last over of the day to move within two runs of the milestone.

However, Anderson was able to keep Mitchell on strike for the remainder of the over to ensure the 34-year-old has something to sleep on. It was the second day in a row that an Australian batsman was left in the 90s overnight after Usman Khawaja wound up on Friday on 91.

Both Khawaja and captain Steve Smith said it would not deter Shaun Marsh.

"He's just out there batting. He's not thinking too much," Smith said. "He's nice and positive against the spin, he moves his feet really well, he's leaving really well. He's just doing all the things you need to do out in the middle to score runs. He's comfortable in his game.

"I know before he got picked Justin Langer said he's batting as well as he's ever seen him bat, and he's seen him since he was about 10 years old. You can't really argue, to be fair.

"He's just waiting for the right ball to hit and geez he hits the ball hard when he gets onto it, as does his brother. He's been exceptional this series. He's got in some big partnerships, made some big scores and hopefully he can go on to get a big hundred [on Sunday]."

Mitchell will also have a chance to wrap up a second ton of the campaign since his recall in Perth.

Both siblings were given out on Saturday but spared by the television umpire.

???Shaun lodged a successful review when umpire Kumar Dharmasena raised the finger, believing England captain Joe Root to have coaxed him into an edge. The replays showed he had hit his pad with his bat instead. ???

Mitchell had a leg before wicket verdict against him overturned when the video umpire, somewhat contentiously, judged him to have hit the ball first. The ball tracker, however, had the delivery clearly wide of leg stump.

Khawaja echoed the sentiments of Smith.

"From a team aspect and obviously from a teammate's and a mate's aspect, those guys, both Marshes, have obviously copped a lot of slack over the last couple of years, Shaun probably even longer," he said.

"For them to go out there and play really well, and play the way that we know that both of them can play, is really rewarding to see. It couldn't happen to better blokes.

"They're great blokes. Actually, the whole family is so nice, so it's really nice to see."