CAPE TOWN, (Reuters) – Ashwell Prince and Jacques  Kallis scored centuries to help South Africa move into a strong  position on the second day of the third test against Australia yesterday.

The hosts ended the day on 404 for three, stretching their  first innings lead to 195 runs over the frustrated Australians.

Australia, who have an unbeatable 2-0 lead in the  three-match series, were bowled out for 209 on the first day.

The South Africans took advantage of a flat pitch under  clear blue skies, with Prince scoring 150 and Kallis unbeaten on  102.

“South Africa have lifted their game and haven’t let us play  as well as we would have liked, although the boys tried very  well,” Australia coach Tim Nielsen told reporters.

“Not many people are bouncing around the changing room and  it’s the first time this young bowling attack has had to  struggle through a long, hard day of test cricket. It’s been a  very tough day today, but it will be character building.” Kallis, the acting South African captain in the absence of  the injured Graeme Smith, completed his hundred shortly before  the close and made no effort to hide his delight having last  reached three figures 13 tests ago in April 2008 against India  in Ahmedabad.

Umpire Asad Rauf originally ruled the single that took  Kallis from 99 to 100 had been a leg-bye, but later changed his  decision to a run after the third umpire confirmed the batsman  had hit the ball with a thick inside edge.

The decision led to a brief tiff between the umpires and  Australia’s captain Ricky Ponting.

SCORED FLUENTLY

Prince, opening the batting for the first time in his career  after being a middle order batsman in his previous 47 tests,  scored fluently as he needed just 152 balls for his century.    The left-hander’s mix of solid technique, sound shot  selection and punchy scoring strokes meant the Australian attack  struggled to contain him.

Prince blasted 19 fours and two sixes in his 249-ball knock  before being controversially dismissed after tea. Third umpire  Billy Bowden overturned Steve Bucknor’s not out decision as the  Australians appealed for a catch down the leg side, believing  the left-hander had got a glove to a delivery from Ben  Hilfenhaus.

AB de Villiers maintained the flow of runs as he cruised to  39 not out, working the ball into the gaps with ease, while  Kallis continued to tear into the bowling. He struck 14 fours  and two sixes off 157 balls. Imraan Khan (20), Hashim Amla (46) were the only other  scalps Australia claimed on day two.

Debutant Khan offered a sharp return catch to Peter Siddle,  while Mitchell Johnson removed Amla after he edged a limp-footed  drive to wicketkeeper Brad Haddin.