Charl Langeveldt picked four wickets to help South Africa restrict defending champions Pakistan to a modest 148 for seven in their Super Eights match of the Twenty20 World Cup, at the Beausejour Cricket Ground, in Gros Islet, St Lucia, on Monday.

Langeveldt crippled the Pakistani batting line-up with accurate bowling. He was very effective, especially in the death to restrict Pakistan to below 150.

While at one end wickets kept tumbling like nine pins, opener Kamran Akmal (37 off 33) went about his business with a cool head. He partnered brother Umar (51 off 33) in a rescue act for Pakistan, who were reduced to 18 for 3 in five overs.

They put on a 51-run stand to help Pakistan post a respectable total.

Umar made 51 off just 33 balls, slamming four sixes and two boundaries. After Kamran's departure for 37, Umar found an able ally in Afridi and the duo kept the scoreboard ticking with occasional boundaries.

However, Langeveldt put the breaks on Pakistan by claiming both Umar and Afridi in the 17th over.

Hereafter, Pakistan failed to accelerate in the death overs and had to be content with giving South Africa a chaseable 149 for victory.

Saeed Ajmal starred with the ball as Pakistan beat South Africa by 11 runs to keep their hopes of qualifying for the semi-finals alive.

Chasing 149 to win, South Africa never got the momentum going and could only manage 137 for seven.

Left-arm spinner Abdur Rehman had done the early damage by removing skipper Graeme Smith and J P Duminy to set panic in the South African camp.

Pakistani spinners Saeed Ajmal (4 for 26) and Abdur Rehman (2 for 35) spun a web around the South African batsmen to pull off a stunning win.

Ajmal was the man of the moment. The off-spinner bowled impeccably to lure the South African batsmen to their doom. He accounted for Jacques Kallis (22), de Villiers (53), Mark Boucher (12) and Johan Botha (19) to record his career-best T20 international figures.

The only noteworthy performance for the South Africans came from AB de Villers (53). He fought a lone battle, hitting one boundary and two big sixes. But it was never going to be enough.

With this win, Pakistan have given themselves a chance to qualify for the semis.

If England beat New Zealand later in the day, Pakistan will play Australia in the semi-finals by virtue of a better net run-rate (+0.041) than the Kiwis (-0.300).