This might have been a hundred Mohammad Rizwan was waiting for, but there was once a time the idea of a No. 6 Pakistan batsman reaching three-figures was something of a banality. Four years ago, Asad Shafiq struck a 137 in an inspired attempt to chase down 490 at Fortress Gabba - or so we called it then - as Pakistan came excruciatingly close to a stunning Test match victory. In one of Pakistan's strongest middle orders, Shafiq had nestled himself in at No. 6 and more than made it his own; that century took him past Garry Sobers as the man with most centuries from that position.

There was little hope of him getting a look-in at that time, but the seed of Rizwan's maiden Test match hundred may have been sown in those days when Shafiq's attractive strokeplay was something Pakistan could take for granted. Comparisons may be both premature and exaggerated, but there are shades of Shafiq in Rizwan's technique at the crease: the economical backlift, the full, open face of the bat, and the reliance on sweet timing. Their physical attributes are uncannily similar too, and with Rizwan tasked with filling in Shafiq's (metaphorically) large shoes, there was only one man to seek out for advice.

"You have to learn how to bat with the tail if you bat where I do," Rizwan told a press conference after Sunday's play in Rawalpindi. "This is international cricket, and at this level you can't afford to make any excuses. At this batting position, our record holder is Asad Shafiq, who has performed in this position for several years for us. Our tour manager Shahid Aslam said I needed to learn a lot of things from Asad. I watched what he did and batting with the tail is very tricky. So I discussed some of those points that Asad taught me, and kept those in mind and utilised them."

If Shafiq is indeed the primary driver behind Rizwan's rich recent vein of form - the wicketkeeper-batsman has five half-centuries and a hundred in his last nine Test innings - it bodes rather well for a future in coaching. Few from the outside, however, could claim credit for the application Rizwan would show when he came in to bat under pressure, as he so often tends to do. Walking out in the twilight on Saturday on what Rizwan called an "unplayable" pitch, South Africa swarmed over the hosts, and with Pakistan reduced to 76 for 5, and then 143 for 7, the knowledge of how to bat with the tail was not only handy but downright crucial.

"When we were batting yesterday, it was an unplayable pitch, everyone could see that. It was a difficult time, and there were edges and streaky runs, but bravery is always rewarded," Rizwan said. "If not for the grace of God, I would have been dismissed and I wouldn't be sat here in front of you. At that point, we thought that a target of 240-260 would be fine. But this morning, the pitch eased up and I found more my faith in my team-mates, even the lower-order batsmen, increasing. That was a huge factor in us stretching that target to 370."

It may only be a statistic, but no batsman ever downplays the importance of their maiden hundred, not least when those runs come on inscrutable pitches like these. While Rizwan produced half-centuries in Australia, England and New Zealand in situations where his side were under the cosh, it may not have escaped people's attention that none of those runs actually helped Pakistan to a Test match victory.

And while useful runs lower down the order are always praised on the day, they tend to be swiftly forgotten if they haven't proved match-changing. Here, however, Rizwan found a way of truly making a difference to the complexion of a contest that had Pakistan sitting much prettier when he had reached three-figures than when he walked out of the changing room. And even if it might have been tongue-in-cheek, the extent to which Test match hundreds separate true batsmen from useful lower-order contributors was made plain by Yasir Shah's banter with his keeper.

"This was a difficult hundred for me. Yasir Shah was joking around with me, saying "I won't consider you a batsman until you score a hundred. Even I can score fifties!""

It is worth remembering, amidst all the eulogies, that the final chapter of this Test hasn't yet been written, even if Rizwan expressed repeated confidence that Pakistan were still well on top in Rawalpindi. With South Africa having laid a solid foundation for the chase - they ended the day at 127 for 1 - on an increasingly flattening pitch, they may feel they can take inspiration from West Indies' stunning chase in Chattogram and make it two glorious away wins in two days. Not if Rizwan has anything to do with it, though.

"This is a Test match, and partnerships happen in Test matches. Just because they have a good partnership doesn't mean we need to panic. They have good batsmen and that can happen. But we have good bowlers, and when that partnership finally breaks we're confident of staying on top of them.

"Thankfully we managed to dig ourselves out of that situation and I was able to score a hundred. The pitch has definitely improved but it can still take spin. I think we attacked a bit too much at the start, but they were able to get away from us. But that can happen in a phase of the game, and we're comfortable that we'll rein them back in tomorrow."

Rizwan isn't a man generally associated with easy confidence, but the fairytale relationship he currently enjoys with Test cricket would make anyone feel ten feet tall. Day five might end up being a famous for Test match cricket in Rawalpindi, but as far as Pakistan's premier No. 6 batsman is concerned, whatever happens tomorrow is unlikely to top today.

Danyal Rasool is a sub-editor at ESPNcricinfo. @Danny61000