It is a measure of South Africa's batting strength that JP Duminy was not in their starting line-up when the tour began. In a similar way that Michael Hussey's first few months of Test cricket left non-Australians wondering how on earth he had been overlooked for so long, Duminy's initial Tests have prompted the same thoughts from Australian cricket followers. How good is your top six when this guy can't find a place?
The same question was asked of Hussey in 2005 and the same answer applies to Duminy - damn good. When they arrived in Australia, South Africa boasted five of the top 11 run scorers in Tests in 2008. Only when one of those men, Ashwell Prince, cracked his thumb, did Duminy get a look in. If Prince is fit for the third Test in Sydney the selectors will face a tough decision on who to leave out. Duminy must play. He believes he won't.
"I probably came out here thinking I wouldn't play, being that I've travelled now for a year without getting a game," Duminy said. "But stranger things have happened in life. Ashwell gets hit the day before the first Test on the thumb and fractured finger and there I was in the Test.
"It probably will happen [that I will be dropped]. If Ashwell's fit to play I'm sure he will play. But I'm just thankful for the opportunity. I've got a taste of Test cricket so I'm just looking forward to the next game."
It's hard to remember a player who has enjoyed a pair of such priceless performances in his first two Tests. His debut effort in Perth was an unbeaten 50 that included striking the winning runs in the second-highest chase of all time. At the MCG he followed with an incredible 166 that in the space of a day took South Africa from a position of extreme vulnerability to a point where they can dream of securing a 2-0 victory by Tuesday.
That in itself is testament to Duminy's ability. His 180-run partnership with Dale Steyn - whose courage in a near four-hour stay cannot be underestimated - was the third-highest ninth-wicket stand of all-time in Tests. It was so unexpected that even the 42,079-strong MCG crowd got behind the pair, despite the consequences for Australia. Duminy said his century at the "colosseum of all grounds" eclipsed his Perth performance and the support of the spectators must have been a factor.
Melbourne fans love to back the underdog - they were captivated by a similarly surprising 107-run last-wicket stand between Hussey and Glenn McGrath against South Africa three years ago. This time they gave Steyn a standing ovation after he was out for 76 and earlier had drummed the advertising boards when Duminy was on 99, roaring their approval when he reached his hundred even though it was off the hometown hero Peter Siddle.
The biggest cheers came from Duminy's team-mates, who had made their way down to the boundary to show their appreciation with whooping and clapping. It was the best they could do without running onto the ground to shower him with hugs and kisses. That most of his batting colleagues had failed should not be forgotten.
The most noticeable thing about the celebrations was Duminy's calmness. He kissed his helmet, raised his arms and acknowledged the applause but not once looked overawed by the moment. Here was a man ready to bat on, and whose maturity belied his 24 years. He did exactly that, guiding South Africa to within 20 minutes of stumps on a day when batting until lunch had been an initial lofty goal.
His century had come with a back-foot cut for four, typical of his strength square of the wicket throughout the innings. He clipped off his pads superbly, defended patiently and displayed the kind of precision placement that marks true class. Australia fielded poorly and dropped catches but none came off Duminy; he was chanceless until the top-edged sweep that ended his innings.
Duminy's other great strength was the faith he showed in his lower-order colleagues Paul Harris, Steyn and Makhaya Ntini, who helped the last three partnerships add up to 275. Singles were taken to expose Steyn, who drove down the ground like a proper specialist and fought through two painful blows on his fingers.
"He showed a hell of a lot of guts today," Duminy said of Steyn. "He got hit quite a bit but also he played and missed quite a bit, so a lot of luck went our way as well. He stuck it out and we kept talking to each other, trying to motivate each other to stay calm, play the moment, play the ball and it worked out for us today."
The South African tail batted like batsmen, comprehensively outperforming the Australian lower order that so frustrated the coach Mickey Arthur on the second day. There are no such concerns for Arthur now. His biggest worry over the next few days could be working out who to drop if Prince recovers for Sydney and it is a pleasing problem to have. It will be a travesty of justice if it's Duminy who misses out.