Warner went to the interval on 92 not out and along with Alex Doolan (30), has stretched the Australian lead to 387 with five sessions remaining.
Warner's flashing blade continued to punish South Africa and he has now scored 490 runs in the series at an average of 98 with a century and three fifties in his last four innings.
The southpaw, who smashed 135 from 152 balls in the first innings, was helped on Tuesday by defensive field settings from South Africa, who employed just a single slip from early in the morning and lost out when Warner edged Vernon Philander through the vacant second slip.
The only wicket to fall in the session was Chris Rogers, who was run out by a bullet throw from the boundary by Dale Steyn when the left-handed opener had 39 having gone past 1000 test runs.
Steyn, who limped off the field in the first innings with a hamstring problem but batted on Monday, managed to bowl three overs at below full pace that went for 24 runs.
South Africa captain Graeme Smith, who overnight announced his retirement from international cricket after this game, will have noted too how easy the Australia batsmen have made the wicket seem.
That is a point which will not be lost on touring skipper Michael Clarke either as he plays weighs up what target to set the South Africans that will give his team enough time to bowl them out a second time.
The series is level at 1-1.
- Sports & Recreation
- South Africa