A belligerent half-century by Kevin Pietersen set England on the way to a good total of 168 for seven.

Then spinners Graeme Swann (3-24) and Michael Yardy (2-31) showed their worth as South Africa were bowled out for 129.

The victory means England have a maximum four points ahead of their final Group E game against New Zealand on Monday.

New Zealand and South Africa have two points while Pakistan are without a win from two matches.