Bangladesh Emerging were 213-4 at stumps after the opening day of the first four-day match against SA Emerging in Chattogram.
Tiaan van Vuuren, Tshepo Ntuli and Andile Simelane all claimed a wicket apiece to keep the visitors in touch on a rain-shortened day when only 70 overs were possible.
Bangladesh, who won the three-match one-day series 2-1, started well thanks to 19-year-old opener Ashiqur Rahman Shibli, who struck 104 off 143 balls.
Together with fellow opener Chowdhury Md Rizwan, the pair put on 69 for the first wicket, before off-break bowler Ntuli (1-70) struck, trapping Rizwan lbw for 12.
Aich Mollah (24) then helped Shibli to nearly double the score to 129. They added 60 for the second wicket, which was broken when Van Vuuren (1-42) had Mollah out lbw.
Captain Shahadat Hossain, with six Test caps to his name, was next in and he stayed in for the rest of the day with an unbeaten 42 off 121 balls.
He first put on 44 with Shibli for the third wicket – a stand that ended when Van Vuuren and wicketkeeper Ntando Zuma had the latter run out shortly after he reached three figures.
And the South Africans then had another wicket not long after when Ariful Islam was caught by Muhammad Manack off Simelane (1-21) for three.
But Pritom Kumar (11*) kept his captain company until the close with the hosts holding a slight upper-hand thanks to their unbroken 38-run partnership.
