Portugal Colonial - Khawaja on cusp of double ton as Australia demoralise Proteas

In another dominant day for the Australians with the series already won, Khawaja peeled off an imperious unbeaten 195 - his highest Test score - while Steven Smith passed a Don Bradman's century landmark with his 30th hundred.

At the rain-enforced close on day two, Australia were 475 for four with Matt Renshaw -- who tested positive for Covid-19 at the start of the match -- five not out.

The runs kept flowing on another demoralising day for the Proteas.

Khawaja and Smith shared in a 209-run stand and Travis Head rammed home the initiative with a blistering 59-ball 70 to leave the visitors yet again facing the uphill task of preventing Australia from claiming a series whitewash.

Khawaja surpassed his previous highest score of 174 made against New Zealand in Brisbane in 2015.

Smith passed Bradman's 29 Test hundreds with a majestic pull shot off Anrich Nortje to the boundary ropes to claim a home-town hundred off 190 balls.

He was out two balls later for 104 when he innocuously chipped back a catch to Keshav Maharaj for the left-arm spinner's first wicket of the series.

Along the way, Smith also overtook Michael Clarke to become Australia's fourth-highest Test run-getter with 8,647 behind Ricky Ponting, Allan Border and Steve Waugh.

Only Ponting (41) and Waugh (32) have scored more Test centuries for Australia than Smith, who is second only to the immortal Bradman (99.94) with a current Test average of 60.89 in his 92nd Test match.

Meanwhile, Khawaja relentlessly accumulated on his third consecutive Sydney Test hundred and when rain ended play with 14 overs left he had faced 368 balls with 19 fours and a six.

Before lunch, Khawaja danced a celebratory jig after clipping Kagiso Rabada for two through deep square to bring up another hundred at his most productive ground, where he averaged 98 going into this Test.

It followed twin centuries against England in last year's corresponding Sydney Test.

"I grew up here just up the road and my family is here watching, I have friends out in the crowd, it's always an honour to score runs here," Khawaja said.

"It's a slow wicket and if we get good weather it will definitely break up and first innings runs will be crucial."

Only England's Wally Hammond, Australian Doug Walters and India's VVS Laxman have scored three consecutive Test centuries at the famous Sydney Cricket Ground.

Head hit another typical rumbustious half-century before he was brilliantly caught on the ropes by substitute fielder Rassie van der Dussen off Rabada.

The Australians have already wrapped up the three-match series after hammering the Proteas by an innings and 182 runs in Melbourne after their six-wicket rout in the opener in Brisbane inside two days.

So far in this one-sided three-Test series, the Australians have amassed 1,303 runs for the loss of 26 wickets -- at an average per wicket of 50. South Africa, in contrast, have 644 runs for the loss of 40 wickets at 16.1.

Apart from the pursuit of a series whitewash, Australia are trying to lock in a place in the ICC World Test Championship final in London in June.

E.Ramalho--PC