CAPE TOWN (Agencies) - Australian captain Michael Clarke has underlined the importance of winning the second Test against South Africa by saying he wont hesitate to make necessary changes in the playing eleven for the crunch game beginning on Thursday. Australia were comfortably beaten in the first Test Friday after slumping to their fourth lowest total with a 47 in the second innings. A match-winning partnership of 150 runs between captain Graeme Smith and Hashim Amla gave South Africa a 1-0 lead in the short series. Clarke conceded Australia were not good enough in the game and stressed on picking the best eleven for the second one at the Wanderers, Johannesburg.