Matthew Hayden on way to his 25th century on Thursday

Melbourne: Andrew Symonds featured with both bat and ball on Thursday to propel Australia to the brink of victory over South Africa on the fourth day of the second Test.

With a day remaining, South Africa were 99 for six in pursuit of 366 for victory at the MCG.

Symonds, under pressure to retain his Test place after a run of low scores, smashed a Test best 72 and then dismissed Jacques Kallis (9) and Jacques Rudolph (4).

He combined with Matthew Hayden (137) in a 124-run partnership off 93 balls in just 66 minutes after lunch to help Australia to 321 for seven declared.

“I had to go out there with a more positive mindset, bite the bullet a bit and be brave, just try and play my way,” Symonds said.

“I went out there and it worked fairly well today (Thursday).”

When South Africa batted, Symonds took two for six from four overs and leg-spinner Shane Warne grabbed the wickets of A.B. de Villiers (8), Herschelle Gibbs (9) and Mark Boucher (5).

Resuming on 110 for two, Australia lost Brad Hodge (24) and Mike Hussey (31) before Hayden and Symonds went on the offensive after lunch.

Their assault on the South African attack, missing Makhaya Ntini who has been ruled out of the third Test with a knee injury, allowed captain Ricky Ponting to declare with 45 minutes remaining in the second session.

Ponting had been criticised for delaying the declaration and not giving his bowlers enough time to dismiss the South Africans in the drawn first Test.

Symonds’ first scoring shot was a six over long-off. Hayden, who had been on 86 not out at lunch, scored his 25th Test century when he square0cut Shaun Pollock for four.

The pair then set about the South African attack, smashing several boundaries before Hayden mistimed a pull shot off Kallis and wicketkeeper Boucher took the steepling catch.

“I’d say from our momentum point of view, it took us a long time to get to that point in the game,” Hayden said of his innings with Symonds, which swung the match in their favour. “It’s significant for us to get a roll on going into their last innings.”

Symonds, who had smashed five fours and six sixes in his 54-ball innings, was well caught by Andre Nel running around the mid-wicket boundary two balls later.

His six sixes are a record by a batsman in a Yest innings at the MCG. India’s Virender Shewag hit five in his 195 in two years ago.

Gilchrist was the third victim in Kallis’ 11th over when he skied a catch to Prince in the deep the ball after Symonds’ dismissal. Kallis finished with three for 58.

Smith and De Villiers began solidly but a stumping by Gilchrist of the right-hander off Warne with the score on 39 sparked a collapse.

Smith was caught by Gilchrist six runs later before Gibbs was bowled by Warne.