Years later, or weeks later, or days later, when they talk about this series, regardless of the result, they will talk about two Dale Steyn spells that started the first two sessions of the third day of the Cape Town Test. Perhaps the 11 best overs anyone can bowl for just two wickets. It was perfect outswing bowling at high pace, often pitching leg, missing off, too often too good for the batsmen. And if it can be considered possible, after that wicketless first spell, Steyn came out to bowl even better. If one were to strain and look for a possible criticism, it was that he bowled just one straighter one and two bouncers in the first chunk of five overs. Everything else was close to perfect. There wasn't even a no-ball; loose balls were a distant thought altogether.
To appreciate Sachin Tendulkar's effort today - his fourth century off his first innings in each of the last four years - it is important to appreciate the most exciting bowler in world cricket at his best. It was just such a day of Test cricket. Of the 66 balls from hell that Steyn bowled in those two spells, which went for 13 runs and took two wickets, Tendulkar negotiated 48. In that mix of some masterful defending, some luck (he could not have survived that without luck), and huge responsibility, is the difference between India's being even and being woefully behind by the end of the third day.
There was no counterattack there: Steyn was too hot to touch for that. It was good old-fashioned buckling down, doing your best and hoping that the good deliveries are too good for the edge. Then again, Tendulkar played five back-to-back Steyn overs for 10 runs - six of them unintentional - and in this modern world, that calls for an injudicious shot to release the incredible pressure. He reserved the releasing of pressure for Lonwabo Tsotsobe, who bowled well too, but in comparison to Steyn he was like Mother Teresa. Calculated risks were taken: the premeditated pull and the upper-cut in Tsotsobe's first over of the day.
Tendulkar had tired Steyn down, Gautam Gambhir had done the same to Morne Morkel, and with some sort of authority established over Tsotsobe's bowling, it was time for Tendulkar to reap the rewards for the hard work in the first hour. As South Africa awaited the new ball, out came the delicate run-scoring shots, the drives through cover and extra cover, the check drives straight down the ground, the nudges, the paddle sweeps, and the steers to third man. Then, as he approached his century and also the second new ball, Tendulkar saw Gambhir get out, and contributed to Laxman's dismissal through a lovely straight hit off Paul Harris. Time, again, for the old-fashioned Test batting to kick in.
This time he was surer with Steyn, coming well forward to defend, using soft hands, and leaving better, sometimes perilously close to off stump. That couldn't be said of Cheteshwar Pujara, who got an unplayable one from Steyn, and MS Dhoni. Three of Tendulkar's four recent new-year centuries have featured partnerships with the tail - in Sydney, in Chittagong and here. It is something we don't appreciate often enough with Tendulkar, because those after him have in the past inflicted heartbreak on him.
Today, Tendulkar took the responsibility again. He shielded Harbhajan Singh from Steyn, and asked him to go after the others. It worked. And in a strange show of outdoing MS Dhoni in terms of defensive captaincy, Smith spread out the fields. That was the only downer on a perfect day of Test cricket, but Tendulkar would have taken it any day. He started manoeuvring the strike, and soon even Harbhajan saw spread-out fields. The partnership bloomed, and Tendulkar got surer, better and more severe on loose deliveries. Even through those deep fields, Tendulkar found runs, hitting Harris for a six over long-off, driving Morkel through the covers, and cutting between the third man and deep point to take couples to retain strike.
If respect from the opponent were a yardstick to measure an effort, Tendulkar came out glowingly from his examination today. Even though on the field, Steyn had a verbal go at Tendulkar, and even though the series is now getting a bit ugly as it approaches its end, Steyn has this to say about Tendulkar's innings: "Sachin is a really good player. I have heard one or two guys remark about the speed and everything I have been bowling at, but he is such a good player, there is no point wasting your energy bowling at him. You tend to save your energy and tend to bowl at other guys. If you bowl a good bowl to him, or a No. 11 batter, it's going to remain a good ball. So it was a good contest going on."
Tendulkar's role in making today one of the best days of Test cricket in recent memory cannot be overstated. But for him, it would have been a much more memorable day for Steyn and South Africa, but we would not have been entertained as much as we were. If Rafael Nadal hadn't come around, we would have remembered Roger Federer's incredible shots, not his matches.

Sidharth Monga is an assistant editor at Cricinfo