Klaasen slammed seven sixes in hitting 69 off 30 balls as South Africa chased down a target of 189 with eight balls to spare
Dhawan made 72 in an Indian total of 203 for five after they were sent in to bat.
India captain Kohli left the field 13 overs into South Africa’s innings after suffering a left leg strain while batting
The series was a personal triumph for Kohli, who hit three centuries and became the first player to score more than 500 runs in a bilateral series
Indian wrist spinners Kuldeep Yadav and Yuzvendra Chahal were effective on a slow pitch, taking four and two wickets respectively.
South Africa's chances of overhauling India's 274 for seven plummeted when they lost their first three wickets inside the first 13 overs.
Zondi said the squad had also been selected with a view to giving exposure to players who might be considered for the next World T20 in 2020.
In a brief statement, Cricket South Africa said it was aware of video footage of Tahir being circulated on social media.
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