In a few ways, it could be. It's a winner-takes all situation, the teams have been at it for the last few weeks so the competition has been sustained and public expectation is high. When South Africa have been faced with exactly the same set of conditions during a World Cup, they have never come out successfully.
But in bilateral series they have had little trouble. Three times over the last three years, South Africa have entered the final match level with their opposition and twice they've won, against India and Pakistan in 2010 and 2011 respectively. Both times it was spoken about as proof that they are not chokers. Still, it did not translate into success at the World Cup.
That's why the outcome in Benoni could have no bearing on the upcoming Champions Trophy or South Africa's state of mind going into it. If they lose, they will probably have less to live up to in England and if they win, it will be a case of more of the same unless they can go on to claim silverware in June.
Where it can make a difference is by testing AB de Villiers' captaincy and the collective capacity of the squad to pull together when it matters. Consistency is out of the window, as a unit and individually, as no-one except de Villiers himself has had a decent run.
De Villiers' showings with the bat are not a reflection on his leadership as he still appears uncertain despite saying he is settling in. He has made too many questionable decisions, most recently getting Colin Ingram to bowl the over that handed Pakistan the advantage in Durban. He changes fields too often and even needlessly, and is sometimes at loggerheads with the bowlers about where they want their men.
De Villiers admitted that he needed time to establish a style of leadership - understandable given the amount of time Graeme Smith spent in the position- but that has surely run out. South Africa will go into a major tournament with a leader who is still uncertain unless he finds himself in seven hours on Sunday.
He could, because the same Smith who has acted as an advisor so far has been ruled out of the final match so de Villiers will need to the job mostly on his own. David Miller thinks he will have some help, though. "Graeme's record and his personality speaks for itself. He is a great role model to many of us but there are also many other senior guys who can fill that spot."
In reality, there are not that many. Hashim Amla is one but he is a reluctant leader, Dale Steyn is another but spends a lot of his time getting hot-headed and then cooling down. Robin Peterson is perhaps the closest to an old hand and how he and the other two support de Villiers will be important, not just with ideas in the field but the way they perform.
So far, South Africa have not had enough from the key players to be comfortable. The main batsmen, Amla, Ingram, and to a lesser extent, Farhaan Behardien, have had one good score sandwiched between sub-standard performances. The bowlers have been impressive in patches - Lonwabo Tsotsobe's opening spells, Rory Kleiveldt's occasional squeezing, and Ryan McLaren's slower-ball bouncer - but they have not consistently threatened. Catches have been dropped in between magical saves. On the whole, they have been a little hit and miss.
What de Villiers wanted from the squad at the start of the series was a straight-line graph. He spoke about establishing a unit that could perform at a certain level for a period of time. What he's got are peaks and troughs but that is not a crisis.
Many pundits believe that a reliable ODI unit is not as a good as one that can up its game at the right time and one need look no further than South Africa as evidence of that. They spend the years in between World Cups clearing away most who come in their path but cannot repeat that in the few weeks over which the ICC event is played. Few can understand why.
Is it because they spent too much effort on the build-up so that they lack freedom once the actual tournament comes around? Is it because they don't understand how to make spur-of-the-moment decisions under intense pressure? Is it because others are just better on the day?
Pakistan may agree with the final argument, especially as they were the team to knock South Africa out of two World T20s and have a reputation for being a side that could win a World Cup final tomorrow, on the moon, if they felt like it.
"When they see a bit of sunlight at the end of the tunnel, their tails seem to wag," Miller said. That tunnel could be a long tour like this one or a major tournament and Miller seemed to suggest that when Pakistan sense there is a way for them to get in and achieve something, they do. Just like that.
That hunch has evaded South Africa and there seems to no secret way to develop it. Apart from maybe making believe that Benoni is Birmingham, while remembering, somewhere in the very back of their minds, that it is not.