Cape Town - Simon Harmer struck on the stroke of lunchtime to keep the Proteas in the driving seat at on the third day of the second Test against Bangladesh in Gqeberha.
Bangladesh had fought valiantly for most of the session with Mushfiqur Rahim and Yasir Ali combining for a 70-run partnership for the sixth wicket.
Keshav Maharaj (1/54) broke the initial resistance when Yasir Ali chipped the ball back to the left-arm spinner to depart for 47.
But it was Harmer (1/35) that dealt the hammer blow in the preceding over before the interval. In fact, it was Mushfiqur who gifted his wicket to the South Africans just after sweeping Harmer to bring up his 25th Test half-century.
The veteran strangely opted for the reverse-sweep which he missed completely and was bowled for 51 off 136 balls.
This left Bangladesh on 210/7, still trailing by South Africa's 453 by 243 runs at the break.