South Africa have slipped from second to third in the latest ICC Test rankings.
Previously, the Proteas had trailed England in top spot by just one point.
However, their series victories over England and Australia four years ago no longer count mathematically, which has resulted in the drop.
That has seen Australia move into second, six points behind England.
South Africa begin their three-match Test series against England at the Kia Oval on Thursday morning.
A 1-0 or 2-1 win for Graeme Smith's side would see them overtake England at the top, while a 3-0 defeat would see them fall to fourth.
