Adelaide: AB de Villiers and Faf du Plessis stonewalled the Australian bowlers for most of the evening session on Sunday, trying desperately to save the second Test and protect South Africa's No. 1 Test ranking.Needing a record fourth innings of 430 to win after Australia captain Michael Clarke declared at 267 for 8 midway through day four, the South Africans slumped to 45 for 4 including the key wickets of skipper Graham Smith (0) and Hashim Amla (17).But old school friends du Plessis (19) and de Villiers (12) put on 32 runs in 29 overs to take some sting out of the Australian attack and help South Africa to 77 for 4 at stumps, keeping their slim hopes of forcing a draw alive. South Africa, still 352 behind with six wickets in hand, needs to avoid a series loss here to retain its No. 1-ranking.The South African batting lineup contains plenty of batsmen who can occupy the crease, but two of them â Smith and Amla â are out and Jacques Kallis is hampered by a hamstring problem that means he has to come in down the order, can't bowl and is unlikely to play in the third Test.Ben Hilfenhaus made an important breakthrough for Australia when he had Smith out in the first over, edging to Ricky Ponting at second slip. Nathan Lyon removed Amla just before tea, then struck again immediately after the interval when he had Jacques Rudolph (3) well caught at short leg by Ed Cowan to make the total 45 for 3. The South Africans didn't add a run before opener Alviro Petersen (24) was beaten by Peter Siddle and lost his stumps.Du Plessis, who scored 78 in his Test debut innings here in Adelaide, and de Villiers must stick around for as many of the 90 overs as possible Monday if South Africa is any chance of repeating the fourth-innings victory of 2008. The South Africans are one of only two teams have scored more than 414 in the fourth innings to win a Test.The West Indies scored 418 for 7 at Antigua to beat Australia in 2003, and the South Africans scored 414-4 in Perth in 2008 for an unlikely win over the Australians. The hosts have been in front of the game since winning the toss and amassing 550 in the first innings, with Clarke scoring 230 to become the first batsman ever to post four double centuries in a calendar year and David Warner and Mike Hussey scoring hundreds.South Africa was dismissed for 388 on Saturday, 162 in arrears, but got back into the game by snaring 5 for 26 late on the third day as Australia wobbled after a decent start to its second innings.The Australians resumed Sunday at 111 for 5 on Clarke (38) was first out, trapped lbw by Dale Steyn to end a 70-run sixth-wicket stand Hussey (54). It was the third time the pair had come to Australia's rescue after a batting collapse in this series, including the 272 stand in the first innings here and the big partnership in the drawn first Test in Brisbane, where Clarke finished unbeaten on 259.Injured James Pattinson scored an unbeaten 29 and Hilfenhaus contributed 18 in an unbroken 47-run eighth-wicket partnership that ensured South Africa would have to chase a 400-plus total.Morkel and Rory Kleinveldt ended with three wickets apiece, while Steyn had 2 for 50 in a bowling attack missing Vernon Philander, who was ruled out just before the match due to a bad back and Jacques Kallis, who hurt his hamstring in the 17th over and has only been able to bat since. Kallis hasn't been able to field or bowl and is expected to miss the third Test, causing concern over the balance of the lineup for Perth after legspinner Imran Tahir's terrible return in Adelaide. Tahir had 0-80 in the second innings, giving him 0 for 260 from 37 overs in the match, among the worst figures in Test history for bowlers not taking a wicket.Australia also will have to reshuffle their bowling combination for Perth, too, after Pattinson was ruled out on Sunday for the next four Tests. The 22-year-old Pattinson sustained a rib injury while bowling on Saturday and didn't return to the field until his nice cameo with the bat.