"Gavaskar recalled that it was a match that India had to win to enter the semi-final" --
HUH? Was/Is Gavaskar out of his mind? Even if India had lost that game, they would have entered the Semi-final. In fact the Next game against Australia in which Yashpal Sharma scored 80 odd runs (if I remember correctly) was the crucial match ...
Had India lost the Zimbabwe match .. India would have ended with 12 points instead of 16 .. but Australia would still have been at 8 !!
But well .. this is not to take the credit away from Kapil - It is one of the greatest innings, if not the greatest ever, as mentioned by Gavaskar!