South Africa pace spearhead Kagiso Rabada rattled Bangladesh's top-order and the batting collapsed to 84 all out in their Twenty20 World Cup clash on Tuesday.

Rabada returned figures of 3-20 and fellow quick Anrich Nortje also took three wickets after South Africa elected to bowl in Abu Dhabi.

Rabada send back Mohammed Naim, for nine, and Soumya Sarkar, for nought, to be on a hat-trick.

Mushfiqur Rahim denied Rabada his third successive wicket on the first ball of his next over but got out three deliveries later without scoring.

Bangladesh suffered another double blow when Nortje claimed skipper Mahmudullah Riyad's prized scalp for three and Afif Hossain fell to Dwaine Pretorius.

Bangladesh slipped to 34-5 and the wickets kept tumbling with Nortje and leg-spinner Tabraiz Shamsi sharing five wickets between them as South Africa wrapped up the Bangladesh innings in 18.2 overs.

Mahedi Hasan top-scored with 27 before being caught and bowled by Nortje.

The Proteas need 85 to get their third win in four group games and boost their chances of moving into the semi-finals.