David Warner has displayed all of his battling spirit to score a terrific double century in his 100th Test, his first Test ton in almost three years, firing back at those who suggested his best days were behind him.
His score of 200 as part of a 239-run partnership with Steve Smith (85) helped Australia to 3-386 at the close on day two, leading South Africa by 197 runs.
Warner also became the second man, after England's Joe Root, to score a double century in his 100th Test.
He could not add to the 200, though, as the long day in searing heat at the MCG took a toll on his body, with cramps exacerbated by his milestone celebration eventually forcing him from the field, retiring hurt but with his job more than done.
Coming into the match off the back of 27 Test innings without a century, dating back to the new year's Test of 2020, Warner not only carried the baggage of his leadership dispute with Cricket Australia, but question marks over his fading form at Test level.
But Warner came out swinging, playing with an attacking fluency that rolled back the years and put to bed, for now at least, any questions over his selection at the top of the order.
Warner's innings could not have come at a better time for the opener, almost certainly cementing his place in India and at next year's Ashes, where his attack-minded attitude at the top of the order could prove vital against the newly positive English under Brendon McCullum.
The innings was not without drama.
Warner was struck on the helmet and gloves, was guilty of running out Marnus Labuschagne before lunch, and rode his luck against particularly fierce bowling from speedster Anrich Nortje — but featured the type of dogged determination that has characterised the 36-year-old's Test career.
Warner's innings could have ended much earlier but for some selfless work from Labuschagne, who sacrificed his own innings to further that of his teammate.
After setting off for a quick single, Warner turned quickly and called Labuschagne through for a second as Keshav Maharaj backed up the overthrow, but the Queenslander had overrun the stumps by at least three strides and was facing the wrong way.
But Labuschagne, after a stutter and a pause and a loud "no" call, put his head down and sprinted to the bowler's end, where he was run out by Maharaj and Nortje despite an extravagant full-length dive.
It was the fifth time that Labuschagne has been run out in Test matches — the most of any player in the period since making his debut.
Warner, meanwhile chalked up his twelfth involvement in a Test run out, with his partner coming off worse on eight occasions.
Despite shouldering the responsibility for the run out, Warner immediately refocused.
Warner copped a blow to the helmet off the top edge early in the day, then had Nortje rap him on the gloves when on 93 as part of an over in which every delivery was clocked at over 150kph.
After repeated treatment on the troublesome left index finger, Warner carried on and, when Nortje was taken out of the attack for a well-earned break, hooked the first ball of Kagiso Rabada's spell for four.
After shouting at the ball "Go!" to will it to the rope, he let out a yell and ripped his helmet off, unleashing the trademark jump and punch of the air that has been absent for the past three years.
He raised both arms, blew kisses to his family and laid a smooch on the badge of his helmet before embracing Smith, his celebration showing relief, joy and typically dogged defiance as he pointed to the grandstand with an upturned bat.
Batting through a day that featured a high temperature of 37 degrees Celsius, he struggled with cramping just before tea but made it to the break with Australia leading by 42 runs.
As the heat and a long innings took a toll on Warner's body, he started swinging for the fences, and Smith joined him.
They scored 80 runs off 10 overs before drinks at the mid-point of the final session, when two chairs were brought out for the batters and Warner was covered in ice and damp towels, and received a massage from the trainer.
The unconventional break seemed to affect the concentration of Smith, who tried to uppercut the first ball upon the resumption from Nortje, but his bottom edge flew straight to de Bruyn at gully to end his stay on 85 after putting on 239 for the third wicket with Warner.
While Smith was furious with himself for failing to reach three figures, Warner's stand-and-deliver approach took him all the way to 200 and, after an initially subdued celebration, he delivered another jump for joy.
It appeared to be the final bit of energy his cramping body could muster, as he came back to earth with a completely broken body, led off the field by trainers without facing another ball and wiping away tears as an emotionally overwhelming day ended in painful fashion.
If the tiring South African bowlers were hoping for respite with Warner's departure, they did not get it from the in-form Travis Head, who crushed five fours and a six off his first 29 balls as he scored at better than a run-a-ball.
Nortje did remove another batter, rapping Australia's first-innings hero with the ball, Cameron Green, on the finger, drawing blood and forcing him to retire hurt as well.
With Mitchell Starc already struggling with an injury to his left middle finger and Green's ailment on the index finger of his right bowling hand, South Africa's greatest hopes perhaps lie in their chances of plundering runs against a diminished bowling attack.
