Mitchell Johnson fireworks have Graeme Smith running scared

Australia 397 South Africa 140-6

Mitchell Johnson celebrates taking the wicket of Faf du Plessis with a 93mph delivery (AP)

Mitchell Johnson's rapid transformation from a figure of fun to Test titan continued unabated as Australia built on their early advantage on a dramatic day at Centurion.

After the events of the past 12 weeks, it now seems hard to remember that the scourge of England's batting order went into the Ashes series with his career in the balance. But after another blistering display of pace bowling ripped out the heart of South Africa's top six, Johnson is clearly here to stay.

Having dismissed Australia for less than 400 after Dale Steyn helped to finish off the tail soon after lunch, home captain Graeme Smith may have fancied his side's chances of at least achieving first-innings parity on a ground where the Proteas have only been beaten once. Given that Smith has twice had his hand broken by Johnson in previous encounters, he should have known better.

It took just four balls for the player who took 37 wickets in the Ashes whitewash to find his range, firing down a brutal bouncer that reared up to hit Smith's bat handle and loop into the hands of a tumbling Shaun Marsh at slip. Alvaro Pietersen followed in Johnson's third over but it was the wicket of Faf du Plessis that will have sent shockwaves through the home dressing room.

Clocked at more than 93mph, the ball was destined for the helmet of Du Plessis and the batsman could only spoon up a dolly catch to Michael Clarke to leave South Africa reeling at 23 for 3. That brought A B de Villiers to the crease, who attempted to rebuild the innings with Hashim Amla until the No 3 was trapped leg before by Peter Siddle.

J P Duminy offered some resistance before he fell to a brilliant catch from Johnson off spinner Nathan Lyon, then the bowler returned to remove Ryan McLaren cheaply. With Robin Peterson joining De Villiers' brave rearguard effort, they somehow survived any further damage and needed no second invitation to leave the field when the rain began to fall an over after another ferocious delivery from Johnson struck the South African wicketkeeper flush on the forearm. "I'm trying to be as intimidating as possible," Johnson admitted afterwards. "I think that [the broken hands] is definitely in the back of his [Smith's] mind, but it was just one of those balls that took off. I think I'll try and keep bowling like that to him and keep producing those kind of balls."

Having shared an unbroken stand of 199 with Marsh, Steve Smith had earlier recorded his third century in his last four Test matches but was dismissed as soon as he reached three figures after edging McLaren. Wicketkeeper Brad Haddin was out for a duck before Marsh's innings was finally ended on 148. But a late cameo from Johnson and Siddle pushed the momentum back the way of the tourists.

Meanwhile, Kevin Pietersen will be the only England-qualified cricketer at this year's Indian Premier League after 10 other English hopefuls, including Luke Wright and Alex Hales, failed to attract a bid at auction.

Centurion scoreboard

First Test (second day of five): South Africa are trailing Australia by 257 runs with four first-innings wickets in hand; South Africa won toss

Australia: First Innings Overnight 297-4

S E Marsh c Smith b Philander 148; 288 balls 0 sixes 15 fours

S P D Smith c Petersen b McLaren 100; 213 balls 0 sixes 13 fours

†B J Haddin lbw b Peterson 0; 3 balls 0 sixes 0 fours

M G Johnson b Peterson 33; 54 balls 0 sixes 6 fours

R J Harris b Steyn 19; 31 balls 0 sixes 2 fours

P M Siddle b Steyn 2; 11 balls 0 sixes 0 fours

N M Lyon not out 4; 3 balls 0 sixes 0 fours

Extras (b4 lb8 w11 nb2) 25

Total (122 overs) 397

Fall 1-15, 2-24, 3-72, 4-98, 5-331, 6-332, 7-348, 8-391, 9-391.

Bowling: D W Steyn 29-6-78-4, V D Philander 24-5-69-1, M Morkel 22-5-73-1, R McLaren 20-4-72-2, R J Peterson 15-0-49-2, J P Duminy 12-1-44-0.

South Africa: First Innings

*G C Smith c Marsh b Johnson 10; 8 balls 0 sixes 2 fours

A N Petersen c Haddin b Johnson 2; 12 balls 0 sixes 0 fours

H M Amla lbw b Siddle 17; 42 balls 0 sixes 2 fours

F du Plessis c Clarke b Johnson 3; 5 balls 0 sixes 0 fours

†A B de Villiers not out 52; 94 balls 1 six 5 fours

J P Duminy c Johnson b Lyon 25; 48 balls 1 six 1 four

R McLaren b Johnson 8; 33 balls 0 sixes 1 four

R J Peterson not out 10; 19 balls 0 sixes 2 fours

Extras (b10 lb2 w1) 13

Total (for 6, 43.3 overs) 140

Fall 1-11, 2-15, 3-23, 4-43, 5-110, 6-126.

To bat V D Philander, D W Steyn, M Morkel.

Bowling R J Harris 12-3-33-0, M G Johnson 13.3-1-51-4, P M Siddle 7-0-21-1, N M Lyon 11-0-23-1.

Umpires Aleem Dar (Pak) and R K Illingworth (Eng).