Fourie appeared before a Sanzar judicial officer at a hearing held in Hamilton the day after the Tri-Nations test.
He was found to have made a reckless lifting tackle which was dangerous and placed Nonu in a vulnerable position when he landed on his neck and shoulder.
Fourie appealed the four match sentence, but in a decision released tonight a Sanzar committee agreed the tackle was a lifting one and in breach of IRB law.
However, it found that in all the circumstances the penalty was inappropriate.
The sanction was amended so that Fourie's suspension runs from September 14, up to and including October 3, 2009.
It means he will be unavailable for two Currie Cup matches on 26 September and 3 October.