The hosts crumbled for 159 and 143 all out in Chittagong to hand South Africa their biggest Test win by margin.
South Africa thrashed Bangladesh by an innings and 273 runs to secure a 2-0 series sweep after enforcing the follow-on and dismissing the hosts for 143 on day three of the second Test in Chittagong.
Seamer Kagiso Rabada decimated Bangladesh with five wickets as the Proteas skittled the hosts for 159 in their first innings to take a huge 416-run lead and they turned up the heat further after asking them to bat again on Thursday.
Bangladesh, who lost the opening game by seven wickets in Dhaka, suffered a familiar collapse and were bowled out in the evening session as Keshav Maharaj bagged 5-59 and fellow spinner Senuran Muthusamy took 4-45.
Sixteen Bangladesh wickets fell on the day at the Zahur Ahmed Chowdhury Stadium.
Rabada dismissed Najmul Hossain Shanto for nine, Mehidy Hasan Miraz for one and Mahidul Islam Ankon for a duck to finish with 5-37 while Dane Paterson got rid of Mushfiqur Rahim for nought as Bangladesh continued to wobble in the first innings.
The hosts, who resumed the day on 38-4, staged a fightback from 48-8 with Mominul Haque making 82 but his dismissal shortly after lunch by Muthusamy ended his 103-run ninth-wicket stand with Taijul Islam.
Taijul was unable to frustrate the tourists further, as he became Maharaj’s second victim after a defiant 30.
South Africa were even more ruthless in the second innings to seal a comfortable victory in three days despite Shanto’s 36, Ankon’s 29 and a late charge by Hasan Mahmud, who was unbeaten on 38 in fading light.
South Africa had three batsmen hit maiden Test centuries in their first innings 575-6 – Tony de Zorzi (177), Tristan Stubbs (106) and Wiaan Mulder (105 not out).
De Zorzi was named the player of the match, while Rabada walked away with the player of the series award.
The tourists won the first Test by seven wickets.
Bangladesh have never won a Test against South Africa in 16 attempts.
The Proteas will look to further boost their chances of reaching the World Test Championship final next year when they meet Sri Lanka and Pakistan in two Tests each at home starting in late November.