Starting the final over of the first playoff game needing six runs to win in pursuit of 147 for victory at Warner Park, Amazon Warriors got home with two balls to spare, after Man-of-the-Match Sohail Tanvir cleared the ropes at long on with left-arm spinner Imad Wasim.
Sohail finished on 21 not out off 13 balls and it was his unbroken 34-run, seventh wicket stand with captain Rayad Emrit (11 not out) which rescued Amazon Warriors.
They were well poised at 85 for two in the 14th over with top-scorer Chris Lynn and Jason Mohammed involved in a 33-run, third wicket stand, but four wickets tumbled for 31 runs in the space of 22 deliveries, to leave the game in the balance.
Lynn struck 49 from 47 balls with a four and three sixes, while Mohammed managed only 13 from 15 balls before triggering the slide when he was caught at short mid-wicket by Shakib al Hasan off left-arm spinner Garey Mathurin.
In the next over with seven runs added, Chris Barnwell holed out to long on off seamer Andre Russell for four and Lynn perished in the 17th over when he, too, was taken in the deep, this time off rookie pacer Kesrick Williams in the 17th over.
When wicketkeeper Anthony Bramble (6) picked out Nkrumah Bonner at fine leg to give Williams his fourth wicket of the innings, Amazon Warriors were slumping at 116 for six in the 17th over, but sensible batting from Sohail and Emrit kept them on course.
Earlier, talismanic captain Chris Gayle top-scored with 33 from 36 balls as Tallawahs, sent in, managed to get up to 146 for eight off their 20 overs.
Rovman Powell chipped in with 23 from 20 balls while Sri Lankan star Kumar Sangakkara struck a run-a-ball 20.
The left-handed Gayle, searching for a decent score following a run of poor form, put on 33 for the first wicket with Chadwick Walton (16) before adding a further 39 with Sangakkara for the second wicket.
When Gayle was bowled by seamer Barnwell in the 10th over, Sangakkara quickly followed in the 13th over, leaving Jamaica in a spot of bother at 84 for three.
Powell combined with Russell (11) to add 36 for the fourth wicket but once they were separated, five wickets fell for 19 runs to hurt the innings.
Emrit snared three for 30 with his medium pace while left-arm seamer Sohail picked up two for 24.
India pulled off a stunning victory even though South Africa seemed to be cruising to a win at one stage. India held their nerves to defend 247 even though South Africa had a positive start to the chase © AFP