South Africa's David Miller warned Wednesday they will look to "exploit" Pakistan's fragile confidence as they strive to seal a Twenty20 World Cup semi-final spot and send their opponents packing.

The Proteas were touted as dark horses in the lead-up to the showpiece in Australia and have showed why with a fearsome pace attack and batsmen in form.

Ahead of other matches in Group 2 later Wednesday, they topped the table with two wins from three matches including victory over India. South Africa's third game was washed out.

In contrast, Pakistan are fifth and their World Cup fate will be sealed if South Africa beat them at the Sydney Cricket Ground on Thursday.

Pakistan's much-vaunted opening pair of Babar Azam and Mohammad Rizwan have failed to fire in three matches at the World Cup and are under pressure to find form, and fast.

"I think it is an area to exploit," said middle-order batsman Miller.

"This game is all about confidence and they haven't probably performed the way they've wanted to.

"But they're world-class players and we're expecting them to come out and bring their A-game and be up for the challenge."

Pakistan bowler Naseem Shah denied that his side are still dwelling on their agonising opening defeat to India.

Pakistan were beaten on the last ball by their arch-rivals and followed that up with a shock defeat to Zimbabwe, before thrashing the Netherlands.

Put to him by reporters that Pakistan have failed to recover mentally from the India defeat, fast bowler Naseem replied: "No, I don't think so because everyone is professional and everyone knows about oneself.

"We lost against India, but I don't think anyone is thinking about the India game because as a professional you can't think about the past when you lose, then especially, you can't be thinking that."

Miller hit an unbeaten half-century in a nervy five-wicket win over India which underlined South Africa's title credentials -- and their resilience.

"I suppose we are finding lots of ways to win," he said.

"We've done it over a period of time now. I'd say probably the last year, we've found ourselves in tricky situations and managed to get over the line.

"I think the continuity of the squad over time, guys have managed to sort of find their roles and if one guy isn't doing well, another guy picks up the slack."