South Africa's slump to seventh in the world means the 1995 and 2007 champions will face the All Blacks in the pool stage for the first time in a blockbuster clash.
The All Blacks will have to beat the Springboks to top their pool, as they bid for a hat-trick of titles.
The All Blacks and England, currently the top two teams in the world, would meet in a tantalising semi-final if they both win their pools and got through their quarter-finals.
New Zealand will likely play Scotland, Ireland or Japan in the quarter-finals.
