Cape Town - South Africa's lower order flexed their muscles on the second morning of the second Test to press home their advantage against Bangladesh at St George's Park in Gqeberha.
The home team resumed on their overnight total of 278/5 and enjoyed a fruitful session moving to 384/7 at lunch.
The Bangladeshis had started promisingly with a review against Kyle Verreynne at the end of the first over, but South Africa's wicket-keeper survived the call.
Verreynne and Wiaan Mulder then proceeded to take South Africa's score to the 300-run mark before Khaled Ahmed delivered a beauty that ripped straight through Verreynne (22) to smash into his middle stump.
Bangladesh had to wait though until the stroke of lunch before they could celebrate any further success when Taijul Islam dismissed Mulder for 33.
However, during the intervening period South Africa's bowling hero Keshav Maharaj from Kingsmead showed that he was still full of confidence by swinging his willow freely.
Maharaj sped to a half-century - South Africa's fourth of the innings - off just 50 balls. He brought up the milestone with a lusty blow for six - his third to go with four further boundaries - over long-on.
Maharaj and Mulder's partnership for the seventh wicket was an invaluable 80 runs off just 100 balls.
Islam remains Bangladesh's most successful bowler with figures of 4/107, while Khaled Ahmed also has 3/91.
Maharaj will resume on 55 not out and Simon Harmer on three after the lunch interval.