It was their first ever series victory over the Proteas in any format.
Bangladesh have now won four home series in a row against Zimbabwe, Pakistan, India and now South Africa, winning 12 out of 14 ODIs in the process. In addition, they beat England at the ICC World Cup earlier this year and took New Zealand right down to the wire in the same tournament.
The fact that they beat South Africa by 7 wickets in one match and by 9 wickets in the next shows just how dominant they have been in the latter part of this series.
Their bowlers again dominated the South African top order up front as they restricted South Africa to a total of 168/9 in a game reduced to 40 overs after a rain interruption and then coasted to victory with 83 balls to spare.
Man of the match, Soumya Sarkar, finished with 90 (75 minutes, 13 fours and a six) while Tamim Iqbal contributed 61 (77 balls, 7 fours). Their partnership of 154 was a Bangladesh record for any wicket against South Africa.