South Africa's bid to lift a first major cricket trophy could come down to whether they can finally shed the unwanted tag of "chokers" and the latest test of their nerves will be against Afghanistan in Wednesday's Twenty20 World Cup semifinal.

The Proteas have competed in seven semifinals over both short format World Cups but have never reached a title match, although they will be happy to avoid Australia this time around having lost to them three times in the last four.

The perennial under-achievers of international cricket are on a hot streak, with solid bowling displays helping them power through the group and Super Eight stages.

Their batting has impressed Aiden Markram less, however, and the South Africa captain is looking to that area for improvement ahead of their semifinal in Trinidad.

"We've been doing really well and the bowling unit has been firing for us, which has been fantastic," Markram said after his team ended the campaign of co-hosts West Indies in a shootout for a semifinal spot on Sunday.

"From a batting point of view, we need to be more clinical. Understanding when the right time is to really take the game on, and maybe understanding when the right time is to knock around for a couple of overs."

South Africa will be encouraged by how several players have stepped up in tense situations to keep their 100% record intact after seven matches so far and they will eye another collective effort to subdue Afghanistan.

"We haven't played our best game of cricket yet," Markram said.

"So we'll try and put our best game of cricket together for that semifinal."

After stunning Australia in their penultimate Super Eight match, the plucky Afghans ensured the 2021 champions were sent packing from the tournament with a dramatic eight-run win over Bangladesh on Monday to join India in advancing from Group 1.

Afghanistan's maiden World Cup semifinal appearance is a sign of how much the sport has grown in the war-torn country and skipper Rashid Khan's side, who also upset New Zealand earlier in the tournament, will target another statement victory.

They failed to register a single win in the last edition of the tournament but were still tipped to make the last four this time around by West Indies great Brian Lara, after whom the Tarouba venue for the semifinal is named.

"Everyone back home is so happy for this big achievement for us being in the semifinal," Rashid said.

"The only guy who put us in the semifinals was Brian Lara, we proved that right. When we met him at a welcome party, I told him 'we won't let you down'."

Rahmanullah Gurbaz has been a key player for Afghanistan, leading the scoring table with 281 runs, and his three century opening stands with Ibrahim Zadran have proved invaluable.

Fazalhaq Farooqi leads the bowling charts with 16 wickets while Rashid has 14, and the pair will be heavily relied upon to pull off yet another upset in Trinidad.

Should Afghanistan prevail, they will play the winners of the other semifinal between 2007 champions India and holders England, who face off in Guyana on Thursday.

"Being in the semi is big for us," Rashid added. "But we have to go with a very clear mind and know what we have done so far which has worked for us. Keep things simple for ourselves and make sure we enjoy that big occasion."