The England cricketers have taken a 4-nil lead in their five-match one-day series against South Africa after winning a rain-hit game by seven wickets at Lord's.
England restricted the tourists to 183 for six from 32.1 overs and when their target was eventually adjusted to 137 off 20 overs, they reached it for the loss of three wickets with two overs to spare.
After Matt Prior and Ian Bell had fallen cheaply in a sluggish start to their response, England took charge.
The key partnership was between captain Kevin Pietersen (40) and Owais Shah, who put on 74 in nine overs, including 20 off the only over bowled by Jacques Kallis.
Shah ended on 44 not out, with Andrew Flintoff hitting the winning runs to finish unbeaten on 31.
The fifth and final match is in Cardiff on Wednesday.