Tony de Zorzi made an unbeaten century to propel South Africa to 205-1 at tea against Bangladesh on day one of the second and final Test in Chattogram on Tuesday.
The opener hit his maiden Test ton off 146 deliveries by sweeping Mehidy Hasan Miraz through square leg for a boundary.
He was unbeaten on 101 with eight fours and two sixes at the break with Tristan Stubbs holding up the other end on 65.
South Africa, victorious in the first Test by seven wickets, won the toss and chose to take first use of a good batting pitch.
Captain Aiden Markram was the only wicket to fall after he went for a big shot off left-arm spinner Taijul Islam and holed out to Mominul Haque at mid-on for 33.
Bangladesh, desperate to take a wicket, have lost two of their three reviews for the innings.
They unsuccessfully appealed for lbw against De Zorzi off a delivery pitched outside leg and again for a caught behind when Stubbs tried to cut Taijul away but missed.
South Africa made two changes to the side that won in Mirpur as they look to seal the series.
In came Senuran Muthusamy, an all-rounder who can bowl left-arm spin, and fast bowler Dane Paterson in place of Matthew Breetzke and Dane Piedt.
Bangladesh made three changes, bringing in batsman Zakir Hasan, fast bowler Nahid Rana and wicketkeeper Mahidul Islam Ankon for a debut.
Jaker Ali, who made his debut in the first match, is out after suffering a concussion while Nayeem Hasan and wicketkeeper Litton Das were also omitted.
South Africa won the opening Test inside four days with fast bowler Kagiso Rabada taking 6-46 in the second innings.
Bangladesh have played 24 Tests in Chattogram but won only two with seven drawn.
