Cricket: South Africa were left praying for better weather after persistent rain ruined their bold attempt to win the third and final Test against Australia yesterday.

Less than 21 overs were completed at the Sydney Cricket Ground, effectively thwarting the visitor's hopes of drawing the series.

Needing a win to square the series after drawing in Perth then losing in Melbourne, South Africa ended the day leading by 186 runs with seven second-innings wickets in hand.

They had been frantically trying to build a bigger lead but now face the prospect of having to make an early declaration on the last day - for which more foul weather is forecast - to give themselves any chance of winning.

"We're in the hands of the weather but basically it just boils down to that we just want to give ourselves a chance of winning the game," South Africa all rounder Shaun Pollock said.

"At the end of the day it doesn't matter if we lose the series 2-0. To protect a defeat and still go 1-0 down in the series is pointless. We might as well give ourselves a chance to win but at the same time you don't want to just make an easy target."

Yesterday's start was delayed by an hour because of showers and less than six overs were bowled after lunch when the heavens opened again. The umpires were jeered by sections of the crowd for not starting play earlier after lunch when the rain initially stopped.

"From our perspective we would have liked to carry on through the drizzle but you've got to understand the outfield gets wet, the ball gets wet," Pollock said. "I thought the umpires handled it pretty well."

Herschelle Gibbs led the South African charge with an exhilarating 67 off 74 balls but ran himself out in the pursuit of quick runs.

Playing a virtual lone hand, Gibbs pounded 11 boundaries in his 98-minute innings before he was caught short of his ground by a direct-hit from Brad Hodge after a mix-up with Jacques Kallis.

Kallis was unbeaten on 14 at the close with Ashwell Prince yet to get off the mark and the score at 94-3.

Kallis and Prince both scored centuries in a record fourth-wicket partnership of 219 which took more than six hours when the tourists employed a go-slow policy in their first innings.

"If we'd known the weather was going to play as big a part you'd have tried everything then," Pollock said. "(But) you can't play Test cricket for the weather. Five days is a long time and to get a big total was what was required after we won the toss."

South Africa had started the fourth day on 4-1 but lost captain Graeme Smith for five with the total on six when he was trapped lbw by Glenn McGrath.

Smith turned down the chance to go off for bad light but gained little reward for his initiative, given out to a ball that struck him high above the knee roll and looked to be sailing over the top of the stumps.

Gibbs then launched into the Australian bowlers with renewed vigour while Kallis, hampered by an elbow injury that forced him to miss the drawn first Test, was content to play the anchor man.

Gibbs had a let-off on 34 when he was dropped by Shane Warne at slip but raced to his second half-century of the series off 58 balls in 73 minutes when he dispatched McGrath to the rope.

McGrath's frustration boiled over when Gibbs was dropped and the Australian paceman was later reprimanded for offensive behaviour. McGrath was found guilty of the offence after appearing before an International Cricket Council (ICC) charged with "using language that is obscene, offensive or insulting and/or the making of an obscene gesture".

McGrath was charged with a level one offence which carried a maximum penalty of being fined half his match fee.