South Africa won a sixth consecutive game over Bangladesh, taking the first Twenty20 by 20 runs on Thursday to be one match from a clean sweep of the tour.Following a 2-0 victory in the Test series and a 3-0 sweep in the one-dayers, South Africa can send Bangladesh home without a win from the entire tour if it claims victory in the final T20 on Sunday.Bangladesh fell short of South Africa’s 195-4 at Mangaung Oval despite a good start, when it was on course at 92-2 after nine overs.Soumya Sarkar’s dismissal for 47 off 31 balls, the best score for Bangladesh, began the slide. Andile Phehlukwayo (2-25) claimed that crucial wicket off the first ball of the 10th over after a successful review for lbw and Bangladesh faded away to finish on 175-9 in its 20 overs.Bangladesh lost wickets regularly after Sarkar’s exit, including two in two balls to seamer Dane Paterson. Seamers Phehlukwayo, Paterson, Beuran Hendricks and Robbie Frylinck, who was on debut, all finished with two wickets for South Africa, which experimented with an inexperienced bowling attack and was missing captain Faf du Plessis to injury.The home team’s total was set up by opener Quinton de Kock’s 59 from 44 balls and AB de Villiers’ 49 from 27 at No. 3. An unbroken partnership of 62 between Farhaan Behardien (36 not out) and David Miller (25 not out) ultimately took South Africa’s total beyond Bangladesh’s reach.De Kock, wearing a shirt with teammate and opening partner Hashim Amla’s name and number on, hit five fours and a six in his half-century and De Villiers hammered eight fours.advertisementSouth Africa recovered from a mid-innings slump with a productive stand between Behardien and Miller at the end. Behardien, especially, scored quickly with two big sixes in his 36 not out from 17 balls.Sarkar led Bangladesh’s response with five fours and two sixes before being trapped in front by Phehlukwayo. After Sarkar, Bangladesh lost six wickets for 58 runs.