Sporting contests are generally considered tussles between two opposing teams. But there is a third dimension which sometimes defines them. Time.
As the stakes become higher, the clock becomes more important. In Durban, it is absolutely vital. Given the draw at the Wanderers and the fact that there is no third Test, everything about this series rests on the result here.
Recent summers in the region have been wet and the possibility of rain interruptions are realistic. There has been at least one on such stoppage on three of the four days played so far. Bad light often calls an early end to the day. So far, the match has been robbed off 57.5 overs - almost two sessions. With that in mind, teams have force a result here.
South Africa's actions in Johannesburg may have made them look hesitant to do that and they reinforced that perception on Saturday, when, on a sluggish surface, play meandered and it became apparent the hosts would primarily work to get themselves into a position from which they could not lose. While they've accomplished that on Sunday, they've also ensured a win is still possible by showing a touch more intent.
Defeat is unlikely for South Africa, thanks to Jacques Kallis. He copped criticism for dead batting the day away when he slowed the run-rate from its peak of four an over when Graeme Smith and Alviro Petersen were batting to two an over by the final hour on day three.
Kallis saw a need to play his usual anchor role and continued doing that this morning. He needed 22 runs to bring up his 45th Test century and moved towards it with caution. It took him 49 deliveries, during which he only had 12 scoring shots. What helped South Africa then was that nightwatchman Dale Steyn kept things moving.
Steyn has a reputation for being able to slog and he took it on himself to be the aggressor. By the first drinks break, he had added 75 runs with Kallis and it seemed South Africa were well-placed for the final assault. Neither Steyn nor Kallis were the men to provide that. The former lacked the nous, the latter the energy.
Kallis had picked up a niggle during his innings, which Robin Peterson said, may require the rest to "carry him through to the end of his last Test" and could keep him from bowling. He received treatment throughout the first interval and appeared to wear a mixture of relief and exhaustion as he climbed the stairs to the changeroom when he was dismissed shortly afterwards.
The fall of both Steyn and Kallis in the space of 17 deliveries, turned out to be welcome for South Africa because it sped them up. Robin Peterson and Faf du Plessis saw out the period before lunch and then came out with an instruction. "The directive was to try and get 100 runs ahead," Peterson said.
Their intent was there; they looked for boundaries rather than waited for them. In the first three overs of the second session, Peterson and du Plessis put on 29. "We got away a little bit and decided that if we had India a little on the backfoot, we can step it up a bit."
Peterson was chiefly responsible for upping the ante. Although the ball was old and difficult to get away, Peterson hit it as hard as he could. India were eventually forced to change the ball when a seam split and that allowed Petersen to accelerate further. He scored quicker than a run a ball and his 110-run partnership with du Plessis came off just 18 overs - a run rate of 6.11.
With the pair motoring on, the South African fielders were spotted in whites and it seemed a declaration, perhaps as they pushed closer to 200 ahead, was on the cards. When Peterson was dismissed, going for a big shot, South Africa were 163 ahead and drizzle was in the air. They should have called time on their innings then because there were about to lose more time.
After a 50-minute break, which included the 20-minute tea interval, they did have reason to regret not putting India in. Du Plessis and Morne Morkel were out in the space of about an over and South Africa had no choice but to take the field, perhaps without as much of cushion as they would have liked.
Still, they would have backed their bowlers to make the 166-run lead count for something and that faith was well-placed. Steyn and Vernon Philander showed all the right intent in their opening spells. Steyn bowled quickly and bowled short, Philander searched for movement and when he found it, looked threatening. The first wicket went to him.
What South Africa will be ruing is that the rest of the attack could not follow up, especially the spinners. Peterson burgled a wicket through a brilliant piece of fielding from Faf du Plessis. "It's not my wicket, it's Faf's," he conceded, and South Africa cannot bank on luck like that if they want to win the match.
They need to make the most of the variable bounce and the aging ball, which could provide reverse swing. They also need to task certain bowlers - Morne Morkel and even Peterson and JP Duminy - with holding an end because if they concede to many, it may require them to do too much, too quickly with the bat.
They know the pressure is two-fold. To beat India, they have to beat the clock too. "We've lost a lot of time in the game. But there is definitely a result beckoning," Peterson said. "Stats show that 10 wickets can fall on the last day in Durban, so we just have to hope we are on the right side of the stats."