(CNN) -- Australia's teenage pace bowler Pat Cummins became the youngest player to take five wickets or more on his debut to leave the second Test against South Africa in Johannesburg finely poised after the fourth day.
The 18-year-old recorded impressive figures of 6-79 as South Africa ended their second innings on 339 all out.
With Australia holding a first innings lead of just 30 runs, that meant the tourists are chasing 309 for victory -- which would constitute a record run chase at the Wanderers Stadium.
And when play ended for the day, Australia had reached 142-3, 168 runs short with seven wickets remaining, thanks to a century stand between Usman Khawaja (65) and Ricky Ponting (54 not out).
Despite Cummins stealing the headlines, South Africa will still consider themselves favorites to go 2-0 up in the series, after last week's eight-wicket win in Cape Town.
Hashim Amla top-scored for South Africa with 105 -- his second Test century of the series and 14th of his career.
"Today has been great for us and we've got ourselves in the box seat," Cummins, told reporters.
"Ricky is looking pretty settled at the crease so it's a very exciting set-up," he added.
However, Amla felt a tight Test match had swung in the home side's favor, saying: "The wicket is not easy to bat on and certain times it seems to act up more than others.
"It seems to be a bit more lively in the mornings. If we can pick up early wickets we can put a lot of pressure on Australia."