Australia clinched a series win over South Africa and remained top of the world rankings after completing a crushing 175-run victory on the fifth and final day of the second Test on Tuesday. South Africa resumed on 244 for two, chasing an improbable victory target of 546 to square the series 1-1, and quickly lost Jacques Kallis for 93 when paceman Mitchell Johnson found the edge with the new ball and slip Ricky Ponting took the catch. AB de Villiers, who had put on 187 for the third wicket with Kallis, then fell for 84 as he pushed forward at fast bowler Peter Siddle and was caught behind by Brad Haddin. Wickets continued to come regularly and South Africa was eventually bowled out 15 minutes before tea for 370. “I am extremely proud of our whole group,” Australia captain Ponting told the post-match presentation. “Coming here we had our backs to the wall but we decided we would give ourselves a really good chance of being competitive in this series. “We have played some amazing cricket and the debutants we have used in the two Test matches have been unbelievable. Whenever you can bounce back from a loss against a very good side like South Africa, it is very satisfying.” Mark Boucher provided last-day resistance for the hosts with 25 in two-and-a-half hours at the crease and Morne Morkel added 24 in 101 minutes. Part-time bowler Simon Katich claimed three unlikely wickets, Australia sealing victory when Dale Steyn attempted a big hit and was stumped by Haddin for seven off the left-arm wrist spinner. Paceman Siddle also finished with three for 61 runs. South Africa skipper Graeme Smith, whose team won the Test series in Australia at the start of the year, was unable to bat on the final day after Johnson broke his finger in the first innings. South Africa's opening batsman Neil McKenzie and off-form fast bowler Morne Morkel have both been dropped for the third and final Test against Australia in Cape Town, but Ashwell Prince returns to captain the side in place of the injured Graeme Smith. Left-handed opener Imraan Khan and seamer Wayne Parnell will both get caps for the first time in the third Test at Newlands, Cape Town beginning March 19.