Adelaide: Usman Khawaja posted the most important century of his cricket career to help Australia's new-look lineup to a 48-run lead against South Africa on the second day Friday of the day-night test.
His unbeaten 138 from 285 balls was Australia's first century of the series, and gave the hosts the daily honors for the first time since the opening day of the three-test series.
The South Africans clinched the series after big wins in Perth and Hobart and are playing a test with the pink ball for the first time.
The Australians, with five changes to the XI, are playing for their international careers.
After resuming at 14-0 on day two, Australia reached 307-6 at stumps.
Kyle Abbott (3-38) took three of the first four wickets for South Africa and Kagiso Rabada and Vernon Philander chipped in with late wickets by getting the second new ball to seam and swing under the lights.
Khawaja was forced into the unaccustomed role of opener when South Africa skipper Faf du Plessis's tactical declaration at 259-9 late on the opening night meant David Warner was not allowed to bat, and he worked with all three new batsmen in the top order.
He batted all day and his only real blemish was the mix up that led to the run out of his skipper Steve Smith for 59, ending their 137-run stand for the third wicket.
Khawaja also shared a 99-run partnership with new No. 5 Peter Handscomb (54) in the second of two stands that lifted Australia from 37-2 to 273-4.
He survived 12 overs under lights before stumps on the first night with 20-year-old newcomer Matt Renshaw (10), who was out first on Friday, superbly caught by a diving Dean Elgar at third slip off Abbott's bowling. Warner (11) was dismissed by the same combination.
Smith went in next and was in dominant touch but, after being given a reprieve on 46 when he was dropped by Hashim Amla at slip, was run out after being turned back when he pushed toward point and took off for a single.
Handscomb navigated a torrid opening over from Philander and, after settling in comfortably against the old ball, plundered the same bowler for three consecutive boundaries to reach a maiden test 50. He didn't last long against the new ball, though. He was bowled by Abbott, triggering a mini-slump as Australia slipped from 273-3 to 283-6.
Nic Maddinson was bowled by Rabada for a 12-ball duck on debut, and recalled wicketkeeper Matthew Wade clouted the first ball he faced for a boundary but didn't add to his score before he was bowled by Philander.
Mitchell Starc had a reprieve when he referred his lbw decision on 4, and was an unbeaten 16 at stumps.
Khawaja's patience was what has been missing for the Australians in the last five tests. He has batted through the entire 102 overs and contained himself to just 12 boundaries, including the cut off Tabraiz Shamsi which took him to his fifth hundred in 20 tests.
He scored 97 in the second innings in Perth, which saved him from the selectors after Australia's batting failures in Hobart.
The stylish left-hander, who scored four centuries and a half century in six innings over the last Australian summer, repaid the selectors' faith with his longest test innings.
