Draw looming as England fail to build on day 1
Both England and South Africa are 3/1 to win the first Test with a draw the odds on favourite at 4/6.
The Proteas are 17/20 to score 406 or more with the captain Graeme Smith 17/20 to score 74 or more.
"All the late money was for the draw but if the weather holds off it is anyone's game," said Hill's spokesman Rupert Adams.
England vs South Africa: 3/1 England, 4/6 Draw, 3/1 South Africa
South Africa 1st Innings Runs: 17/20 405 or less, 17/20 406 or more
Smith first Innings Runs: 17/20 73 or less, 17/20 74 or more
Amla first Innings Runs: 17/20 83 or less, 17/20 84 or more
Next Man Out: 10/11 smith, 10/11 Amia