Travis Head defied the hostile pitch conditions to produce a run-a-ball 78 that moved Australia to within seven runs of South Africa's first innings Saturday, when 15 wickets fell on the opening day of the three-Test series. (More Cricket News)

Head's unbeaten innings containing 13 boundaries and a six and his 117-run partnership with Steve Smith (38) helped justify Pat Cummins' gamble to bowl first after winning the toss. Australia was 145-5 at stumps.

Overhead and ground conditions were perfect for bowling early and the green, grassy pitch at the Gabba was well exploited by both attacks, with 13 wickets falling in the first 60 overs as Australia bowled out South Africa for 152 and then slipped to 27-3 in reply.

Left-arm paceman Mitchell Starc (3-41) and off-spinner Nathan Lyon (3-14) took three wickets each for Australia to set the tone for the bowlers and then South Africa paceman Kagiso Rabada (2-50) struck on the first ball of the home team's innings to remove David Warner for a golden duck.

South Africa allrounder Marco Jansen (1-15) struck with his first ball of the match, in the 9th over, when Marnus Labuschagne (11) edged to Dean Elgar in the slips and then Anrich Nortje (2-37) struck with his second ball of the match, in the 10th over, with a delivery that lifted sharply and which Usman Khawaja (11) edged to third slip.

Head then joined Smith at the crease and the fourth-wicket pair combined for the biggest partnership of the day, surpassing the 98-run fifth-wicket stand between Kyle Verreynne (64) and Temba Bavuma (38) that salvaged and then prolonged South Africa's first innings.

The Australians lost two wickets in the two overs before stumps, with Smith bowled by Nortje seven minutes before stumps and Rabada having night-watchman Scott Boland caught behind on the last delivery of Day 1.

“Entertaining day of cricket!” Head said in a TV interview.?

“Disappointing to lose the two (wickets) at the end there but we fought hard. It was a difficult wicket, so I think we'll take that. We have to come out and have a good couple of hours in the morning.”

Head described the pitch as “very ... very tough.”

“There's a fair bit there ... a little bit up and down,” he added. South Africa “bowled extremely well. We tried to be as positive as we possibly could be.”

There's always plenty of tension when Australia and South Africa meet, and this is a contest featuring the top two teams in the World Test Championship standings.

It's also the first test series between the two countries since the so-called Sandpapergate scandal in South Africa in 2018 that rocked Australian cricket, and the ball-tampering saga was the main talking point ahead of the first Test.

Cummins made an effort to steer the conversation around Australia's bowling attack in a different direction by taking the risk of bowling first after winning the toss at the Gabba. He was the first Australian captain to do that in 22 years since Stephen Waugh led Australia to an innings victory against West Indies in 2000.

It had an instant impact, with Starc dismissing South Africa skipper Elgar in the fifth over, gloving a legside catch to wicketkeeper Alex Carey, and then Cummins and Boland taking three wickets in 11 balls to have South Africa reeling at 27-4.

The fifth-wicket pair stemmed the flow until Starc ended that defiance when he dismissed Bavuma and then off-spinner Lyon accelerated another slide with three wickets.?

Lyon returned 3-14 from eight overs, troubling the lower order, with Starc collecting 3-41 from 14, narrowly missing out on his 300th test wicket when Head put down a sharp, juggling catch at short leg. Cummins (2-25) and Boland (2-28) each took a pair as the front-line bowlers all chipped in.

South Africa will start Day 2 aiming to take the remaining five first-innings wickets before the pitch settles down and starts making it easier for batting.