Team balance a problem for both sides as India and South Africa have yet to play to their potential.
Selection issues for rivals India and South Africa
Sachin Tendulkar made 28 at Hove in 1999, while the man who now coaches him, Gary Kirsten, scored just three. The game-changer was Jacques Kallis, whose 96 saw South Africa home by four wickets, with 16 balls to spare.
At the time, it was not the result that grabbed the headlines.
• Cricketers in the glare of their fans
• Points table
• Bangladesh score a thrilling win over England
• West Indies reach quarter-finals with win over Ireland
"A festive atmosphere and a cracking finish were overshadowed, for the press at least, by the strange case of Cronje's earpiece," said the Wisden Almanack.
"Cronje and Donald were wired up to coach Bob Woolmer, who sat in the dressing-room dispensing advice. The referee, Talat Ali, was not impressed and pounced at the first drinks break. ICC later ruled out remote-control captaincy, at least for the rest of the World Cup."
Kirsten will not be resorting to technology or telepathy in Nagpur, but with the jostle for quarter-final places well and truly underway, the focus is on two sides that are the competition's great underachievers.
India hold the keys to cricket's safe and have the largest pool of talent from which to pick yet have reached just one final, which was a losing one for them in 2003, since Kapil Dev held the trophy aloft in 1983.
South Africa have frequently been ranked No 1 in the days since they emerged from a 21-year isolation but have just three semi-finals to show for their five World Cup appearances.
After starting the tournament like a runaway train, they hit the buffers dramatically on a slow and low Chepauk pitch against England.
India are unbeaten after four games, but have yet to deliver a comprehensive all-round performance. On a Nagpur pitch that has been a batsmen's paradise, their bowling resources will once again be stretched to the maximum.
The continued selection of Piyush Chawla has generated fierce debate, but if India do stick to the two pace-two spin plan, it is almost certain that he will continue ahead of Ravichandran Ashwin, the tall off-spinner from Tamil Nadu.
On a surface that offers more bounce than most in India, MS Dhoni, the India captain, hinted at playing three pacers, with Munaf Patel returning to support Zaheer Khan and Ashish Nehra.
South Africa also face a selection dilemma, with Imran Tahir nursing an undisplaced fracture in his left hand.
"He has bowled this week and come through it fine," said Graeme Smith, the South Africa captain, refusing to rule him out.
If Tahir isn't risked, the choice will be between Johan Botha's off-spin and Lonwabo Tsotsobe, who enjoyed success against India at home not long ago.
Tahir has been one of the finds of the tournament, his form in sharp contrast to that of Harbhajan Singh, who has two wickets from four games.
"He knows that when you're one of the big players in the side much is expected of you and often it means getting two to four wickets in the game," Dhoni said.
"He's doing his job. If the batsmen are not willing to take risks, he's at least stopping the opposition from scoring runs. It helps the bowlers on the other side."
Smith spoke of the good memories that the venue evokes - South Africa won a Test by an innings and six runs in 2010, with Dale Steyn taking seven for 51 - and was not unduly perturbed by the batting meltdown against England.
"The middle order aren't going to encounter more challenging conditions than that during this tournament," he said. "The spirit around the group is great."
Tendulkar was an 18-year-old middle-order bat the first time these two sides clashed in a World Cup.
Kirsten's half-brother, Peter, played the decisive innings that day at the Adelaide Oval. A generation on, both teams are still trying to complete the big picture. Bragging rights are at stake today, but it will be what they take out of the result that reveals whether either side has what it takes to end Australian domination.