Samson made 109 not out and Varma hit an unbeaten 120 in an Indian total of 283 for one, which included 23 sixes – a record for a team in T20 internationals between Test nations.
Arshdeep Singh and Hardik Pandya reduced South Africa to 10 for four in reply, effectively ending the match as a contest. The hosts were bowled out for 148, going down to their heaviest defeat in the format.
India won the series 3-1 despite fielding a youthful team, with most of their established stars preparing for a Test series in Australia.
Their squad included only four of the players who defeated South Africa in the T20 World Cup final in Barbados in June.
“This is a special win and it will stay with me forever,” said India captain Suryakumar Yadav.
“Our plans were very clear and although we were 2-1 up in the series we wanted to continue the good habits and not think about the results.”
South Africa captain Aiden Markram admitted his team were outplayed.
“They put us under pressure from the very start of both innings,” he said.
It was the second century of the series for both Samson and Varma, with player of the series Varma making a second successive hundred while Samson was coming off two ducks after opening the series with a hundred.
It was the second-highest T20 total between Test nations, just 14 runs short of the 297 for six that India made against Bangladesh in Hyderabad last month.
The tone was set by Samson and Abhishek Sharma (36), who put on 73 for the first wicket in 5.5 overs with Sharma hitting four sixes.
Samson hit nine sixes in his 50-ball innings, while Varma cleared the boundary on 10 occasions while facing 47 deliveries.
The start of the South Africa innings was in complete contrast to the Indian run spree with both Arshdeep and Pandya generating swing under the floodlights.
Left-armer Arshdeep bowled Reeza Hendricks with the third ball of the innings, Pandya had Ryan Rickelton caught behind in the second over and Arshdeep dismissed Markram and Heinrich Klaasen with successive balls in the third over.
Brief scores:
India 283-1 in 20 overs (T. Varma 120 not out, S. Samson 109 not out, A. Sharma 36) v South Africa 148 in 18.2 overs (T. Stubbs 43, D. Miller 36; Arshdeep Singh 3-20).
Result: India won by 135 runs
Series: India won the four-match series 3-1
Toss: India
AFP
