Jacques Kallis [Images] and AB de Villiers [Images] scored unbeaten half centuries to take South Africa [Images] to 244 for two at the close of the fourth day of the second Test against Australia [Images] on Monday.

• Scorecard: Australia vs South Africa, 2nd Test

Kallis, who was dropped first ball by Marcus North at slip off Peter Siddle [Images], made the most of the let-off to share an unbeaten stand of 164 with De Villiers as South Africa chased the 546 they need to win and level the three-match series.

After losing openers Hashim Amla [Images] (43) and Neil McKenzie [Images] (31) to early strikes by Siddle, South Africa recovered with Kallis and De Villiers looking comfortable batting in bright sunshine and maintaining a run-rate of around three per over.

Kallis was on a defiant 84 not out at the close and De Villiers had made a fluent 68 as the South African pair dominated proceedings for 3-1/4 hours at Kingsmead.

North was probably the most frustrated Australian of all after putting down a knee-high slip catch from Kallis on his first ball. The ball came to him quickly but he appeared to react late.

South Africa need to score 302 runs on the final day to win or survive for 90 overs to snatch a draw.

Siddle was the pick of the Australian bowlers, claiming the wickets of opening batsmen Neil McKenzie (31) and Hashim Amla (43) before tea to finish with two for 39 in 16 overs.

He had McKenzie caught by keeper Brad Haddin in the second over of his third spell and Amla caught by Ricky Ponting [Images] at second slip in the fifth over of his spell as Australia threatened to tear through the top order.

But Kallis and De Villiers settled the hosts' nerves with some counter-attacking strokeplay.

Australia had resumed on 292 for three and batted on for 35 minutes before declaring their second innings on 331 for five, leaving them with a massive lead of 545 runs.

Opener Phillip Hughes, who has hit back-to-back centuries in this Test, cashed in as he added another 24 runs in 20 balls.

He belted Makhaya Ntini's [Images] first ball of the day through extra cover for four and was soon smashing Dale Steyn [Images] back over his head for six to raise his 150 after six hours and 312 deliveries at the crease.

The left-hander stepped away and slashed once too often, though, slicing a catch to third man off Ntini to be dismissed for 160 in the seventh over of the day.

AB de Villiers then took a nonchalant one-handed catch at second slip to dismiss North for a duck off Steyn.

Michael Clarke [Images] was not out 23 when the innings was declared.