Warner crushes South Africa with 200 in milestone test

An emotional and exhausted David Warner retired hurt after a majestic 200 as Australia dominated on day two of the second test against South Africa in Melbourne.

Australia were 386 for three at stumps on Tuesday, in reply to the Proteas' first innings 189 - a lead of 197 runs and with the three-match series at their mercy after a six-wicket win in the Brisbane opener.

Short of runs and without a century in nearly three years, a tiring Warner slogged his way to his third double-hundred from 254 balls before succumbing to cramp and limping off the Melbourne Cricket Ground field with the aid of a trainer.

He notched his 25th hundred during the innings and became the eighth Australian to reach 8,000 test runs, ending a debate about his place in the side following his lean run in the home summer.

He and Steve Smith put on 239 runs for the third wicket before Smith was caught in the gully for 85 off express paceman Anrich Nortje.

"He just played beautifully," Smith told reporters of Warner. "The more he started to cramp, the more shots he started to play and everything seemed to be coming out of the middle (of the bat)."

Warner was the first of two Australian batters to retire hurt on day two, with all-rounder Cameron Green (six not out) also coming off late after being struck on the index finger by Nortje.

The retirements were small mercies for the Proteas, with Smith the only wicket taken by a bowler after Australia resumed on 45 for one in the morning.

The other wicket was a run out, with number three Marnus Labuschagne falling for 14 before lunch when Warner made an ill-judged dash for an extra run from an overthrow.

Australia's in-form number five Travis Head saw off 11 overs of the second new ball to be 48 not out at stumps, with wicketkeeper Alex Carey on nine.

The pick of South Africa's bowlers, Nortje regularly clocked over 150 km/hr despite the heat and was unlucky not to finish with more wickets.

The speedster was also knocked over by the host broadcaster's 'Spidercam' after lunch as the cable-suspended camera swooped low and clattered into his back at speed.

Though left with a sore elbow, Nortje said it didn't affect his bowling.

"I moved my head and then I saw the camera and I was a little bit too late. It was quite quick," he said.

"The one thing we've spoken about is how low it is .... I don't think it should be travelling head-height."

After resuming on 32 in the morning, Warner brought up his first hundred by pulling pace spearhead Kagiso Rabada to the fine leg fence, and he celebrated wildly, blowing kisses off his bat as the terraces roared.

On 124 he lay down by the pitch to have trainers work on his cramped legs, but rose to his feet to complete his second hundred with a four off seamer Lungi Ngidi before retiring.

With paceman Mitchell Starc nursing a sore middle finger on his bowling hand, the finger injury to Green - who took a career-best five-wicket haul on day one - could leave Australia short-handed in attack.

South Africa's batsmen, however, have failed to reach 200 in seven successive innings.

"It's going to be crucial to try and bat as long as we can," said Nortje. "The more overs the (Australian) bowlers are going to bowl, the more maybe a back-up bowler or someone who doesn't really come on will have to apply themselves."