Harshal Patel and Yuzvendra Chahal starred as India wrecked the South Africa top order in Visakhapatnam, sealing a massive 48-run victory to reduce their T20I series deficit to 2-1.
The hosts needed to win to keep their hopes of a series triumph alive after going down to Heinrich Klaasen's career-best 81 in Sunday's four-wicket defeat.
And superb bowling displays from Harshal (4-25) and Chahal (3-20) meant they did exactly that after Ruturaj Gaikwad (57) and Ishan Kishan (54) hit half-centuries for the hosts, who scored 179-5.
The tourists produced a disappointing performance with the bat as they toiled to 71-5 and ultimately fell well short of their much-improved hosts, eventually bowled out for 131 in the final over.
Having been put in to bat by South Africa, Gaikwad and Ishan wasted little time in establishing a strong platform for the hosts, the former becoming the first dismissal of the contest in the 10th over, by which point India had 97 on the board.
While Dwaine Pretorius (2-29) eventually claimed the wickets of both Ishan and skipper Rishabh Pant (6) to keep the Proteas in contention, their hopes of wrapping up the series early were quickly shattered when they took up the bat.
The dismissal of skipper Temba Bavuma for just 8 set the tone for a dismal South African display, with Reeza Hendricks (23), Rassie van der Dussen (1), Pretorius (20) and David Miller (3) all following in a miserable start.
With India in full control, Chahal and Harshal ran riot, the latter claiming his fourth wicket when dismissing Tabraiz Shamsi for a golden duck with the final ball of the contest as the dominant hosts kept the series alive.
Dominant duo run riot
Having struggled to make headway against South Africa in the first two contests of the series, the Indian attack was back to its best in this potentially decisive third clash.
Harshal set the tone by sending Bavuma and Hendricks tumbling early before finishing with four, while Chahal stepped up to claim his own treble, ensuring there was to be no repeat of Klaasen's heroics by dismissing him for 29.
Home openers on form
Gaikwad and Ishan's gave India a superb platform to build from, with the former recovering from his poor start to the series – in which he had previously scored just 24 runs across two innings – as the pair each hit crucial half-centuries.