David Miller smashed the fastest century in Twenty20 international cricket as South Africa outclassed Bangladesh by 83 runs in the second and final Twenty20 international at Senwes Park, here.

Miller’s 35-ball hundred propelled South Africa to 224 for four before Bangladesh were bowled out for 141 on Sunday, completing a clean-sweep for South Africa in two Tests, three one-day internationals and two T20 internationals.

It was an extraordinary innings by Miller.

Dropped on nought, he admitted: “I felt pretty scratchy to be honest. In the first ten balls I could have been out twice.”

He had only scored 18 runs off 14 balls, then came an assault which yielded 82 runs off 21 balls to get to his century.

“Once I hit one or two I decided to keep going,” he said.

The previous fastest T20 international century was made off 45 balls by fellow South African Richard Levi against New Zealand in Hamilton in 2011/12.

Five of Miller’s nine sixes came off the first five balls of the 19th over, bowled by promising all-rounder Mohammad Saifuddin, who had dismissed AB de Villiers and Hashim Amla and conceded only 22 runs in his first three overs.

Miller said he felt the rare feat of six sixes in an over was possible.

“I got to the fourth one and thought I might as well go for it. The fifth one came out nicely.”

Saifuddin pushed the last ball of his over wide of the off stump and Miller mistimed it for a single.

“Looking back I probably could have hit six off six,” said Miller.

The left-hander’s innings could have ended off the second ball he faced as he gloved an attempted pull off Rubel Hossain.

Bangladesh wicketkeeper Mushfiqur Rahim dived to his right and appeared to have caught the ball but lost control as he landed on the ground.

Miller shared a 79-run fourth wicket partnership off 41 balls with Hashim Amla, who made 85 off 51 balls with 11 fours and a six.

Bangladesh captain Shakib Al Hasan admitted it had been a poor tour for his team.

“Today was a reflection of the series. We need to learn a lot from this. We have been terrific for the last two years at home but now it is time to get better overseas.”

Bangladesh made a good start, restricting South Africa to 37 for two in the first five overs.

Shakib opened the bowling and sent down all his four overs in one spell, taking two for 22. But his teammates could not sustain the pressure in the face of Miller’s onslaught.

Bangladesh scored 17 runs off the first over, bowled by Beuran Hendricks. But Imrul Kayes was run out in the second over and the tourists never threatened again.

Miller was only the fourth South African to hit a century in 100 T20 internationals.