PERTH: Dean Elgar and JP Duminy both recorded half centuries as they batted through the third morning of the first test against Australia to take South Africa to 183 for two and a lead of 181 runs at lunch on Saturday.

Elgar reached the break unbeaten on 69 in a 138-run partnership with Duminy, who overhauled his team mate in the last half an hour of the session and headed for the dressing room 74 not out.

After 22 wickets had fallen at the WACA over the first two days of the test, more might have been expected when the Proteas resumed on 104 for two in brilliant sunshine.

Lefthander Elgar, who was dismissed for 12 in the first innings, played a measured, almost chanceless innings punctuated with eight boundaries, however.

The 29-year-old brought up his fourth test half century when he punched his fifth four through square leg, and three overs later Duminy joined him at the milestone.

A sublime straight drive earned Duminy his eighth test half century, as well as his 10th four of innings, and he added two more before the break.

The best chance of ending the partnership came when Dave Warner fired a direct hit at the stumps as Duminy charged down the wicket but the batsman comfortably made his ground.

Australia's pace trio of Mitchell Starc, Josh Hazlewood and Peter Siddle bowled reasonably well but without success and captain Steve Smith decided against bringing spinner Nathan Lyon into the fray.

South Africa skittled Australia for 244 in reply to their 242 on Friday but also lost key paceman Dale Steyn for the rest of the series with a fractured shoulder. Steyn said on Saturday he thought he would be out for at least six months.

After Perth, where South Africa have won on their last two visits in 2008 and 2012, the series continues in Hobart before concluding with a day-night test at Adelaide Oval.