South Africa completed the joint-highest chase in the history of one-day internationals in India as they passed a target of 359 to win by four wickets in Naya Raipur.
Aiden Markram hit 110 from the top of the order, while Matthew Breetzke and Dewald Brevis both made half-centuries as the tourists beat India with four balls to spare.
Virat Kohli and Ruturaj Gaikwad had both made centuries in the home side’s innings, but having closed on 358-6, they were unable to defend their score as South Africa completed the joint sixth highest chase in the format’s history to level the three-match series at 1-1.
India lost a 20th consecutive toss as KL Rahul’s side were put into bat by their opponents, but would have been confident of victory after Kohli and Gaikwad put on 195 for the third wicket.
Kohli extended his lead at the top of the ODI century scoring charts, making his 53rd hundred in the format having 135 in the first match of the series, while Gaikwad’s 105 was his first three-figure score in 50-over internationals.
Gaikwad was caught by Tony de Zorzi off Marco Jansen, while Kohli was taken by Markram of Lungi Ngidi for 102, before Rahul struck an unbeaten 66 to finish India’s innings strongly.
South Africa lost Quinton de Kock for eight, caught by Washington Sundar off Arshdeep Singh, in the fifth over of their reply, but Markam put on partnerships of 101 with captain Temba Bavuma (46) and 70 with Breetzke (68).
Markram was caught by Gaikward at the end of Harshit Rana’s 30th over, but Brevis arrived at the crease to hit a 34-ball 54.
The 22-year-old was dismissed when he hit Kuldeep Yadav to Yashasvi Jaiswal, before Breetzke and Marco Jansen were dismissed by Prasidh Krishna and Arshdeep in the space of five balls.
But Corbin Bosch steadied South African nerves, striking an unbeaten 29 from 15 balls, including a match-winning four, as his side reached to 362-6 to seal a remarkable victory.
The series concludes in Visakhapatnam on Saturday, before a five-match T20 series.