Australia 145 for 5 (Head 78*, Nortje 2-37, Rabada 2-50) trail South Africa 152 (Verreynne 64, Bavuma 38, Lyon 3-14, Starc 3-41) by seven runs
Brisbane: It brought 15 wickets and almost 300 runs on a tough Gabba pitch, but round one of the NRMA Insurance Test battle between Australia and South Africa rests marginally in the former's favour thanks to some bold final session batting.
After South Africa were knocked over for 152 on the stroke of tea, Australia found themselves in the same strife as their rivals had endured at day's beginning before Travis Head's blazing unbeaten 78 and partnership with Steve Smith (36) took them to 5-145 at stumps.
It would have been a more emphatic advantage to the hosts had Smith and night watch Scott Boland not lost their wickets in the final two overs as Proteas quick Anrich Nortje pushed above 150kph.
On a day as wildly fluctuating as it was utterly absorbing, both teams traded heavyweight blows through their artilleries of hefty pace men before Australia emerged ascendant on points thanks to the exhilarating stand between Smith and Head.
Coming together at 3-27 and in the same dire state South Africa had plumbed in the opening hour, the pair weathered the storm of regular haymakers before landing a flurry of their own in the final hour as their partnership yielded 117 from 138 balls before Smith's had his stumps rattled.
Head revived memories of his game-changing hundred in the final session of day two at last year's Ashes encounter at the same venue, reaching 50 from 48 balls faced courtesy of an effortless flick over backward square leg for six.
Today's knock also continues a rich of first innings scores in recent weeks, with the left-hander peeling off 99 (off 95 balls) against West Indies at Perth followed by 175 (off 219) against the same opponent at his home ground in Adelaide a week later.
Mitchell Starc will also begin Australia's next bowling innings – which at the current rate this game is unfolding could be midway through tomorrow – needing just one wicket to reach 300 in Tests having claimed 3-41 in South Africa's total of 152.