Ask any Indian supporter when the turning point of the game arrived and he'll have little doubt. Jacques Kallis had scored just 2 when a thick inside-edge exploded off his thigh-pad into the grateful hands of Gautam Gambhir at short leg. South Africa should have been 89 for 3, but they weren't. They stayed at 89 for 2.
Kallis was given not out, and added a further 50 runs to his score before the close. He will resume on the fifth morning with his country clinging desperately to hopes of an extraordinary and unlikely victory.
Was it cheating? Adam Gilchrist might say so, but Kallis has always been a believer in allowing the umpires to earn their match fees, and he makes them work harder than almost anyone else. Seconds after his indiscretion, his bat was raised high in the air, apparently out of harm's way, and Daryl Harper was convinced - bluffed, if you like.
If Kallis escaped once, however, how many times did India's close fielders try their luck? Driven by a strong sense of injustice and the tension of the occasion, everything that went to hand resulted in a chorus of orchestrated and cynical appealing that made life unpleasant for the officials, at best, and impossible at worst.
Kallis has had some rough decisions in his time - five years ago, he became Courtney Walsh's 500th Test victim when a similarly huge edge went undetected by the umpire and he was given out lbw. Since that day Kallis has been a hardened believer that you take the rough with the smooth and do your crying behind closed doors in the dressing-room.
It will all be forgotten if Harbhajan Singh and Anil Kumble wrap up the tail quickly to conclude what would be a well-deserved series victory, but if Kallis emulates Gary Kirsten's feat of scoring a pair of centuries at Eden Gardens, that moment will constitute the turning point of the series, not just the match.
Which brings us back - for the umpteenth time - to the absurdity of this game that we all love so much. A hundred journalists in the press box, and a worldwide audience of millions, knew within seven seconds of the verdict that it was wrong. All the players involved knew it was wrong, too. The only man in the dark was the umpire.
And yet we cling to the notion that umpires' decisions, right and wrong, are part of the charm of the game. It is not charming. It is embarrassing.
Neil Manthorp is a sports journalist based in South Africa, and is a partner in the MWP Sports Agency.