Nonu was suspended for three weeks for a dangerous tip tackle in the match between the Highlanders and the Crusaders on Saturday night.
After a hearing on Sunday night, judicial officer Jannie Lubbe slapped Nonu with a three-week ban.
Lubbe, a South African, said the tackle was poorly executed but the tackled player was not injured. The tackle was at the low end of offending and the starting range for punishment was four weeks.
Nonu's disciplinary record already included a sending-off at the start of the 2011 season, when playing for the Hurricanes against the Highlanders, but he was given credit for his remorse and guilty plea.
General manager Roger Clark said yesterday the Highlanders accepted the penalty. The hearing had taken into consideration the mitigating circumstances around the tackle, he said.
Nonu will remain with the squad, although he is out of the final two games of the season.
Meanwhile, Highlanders loose forward Jarrad Hoeata has been suspended for one week after a hearing last night. He appeared before a judicial officer after receiving his third yellow card for the season on Saturday night.
• Harbour flanker Hadleigh May has lost an appeal against a suspension he received at the world junior championship and is out of rugby until September 14.
May was suspended for eight weeks after he was found guilty of eye gouging against Ireland. He appealed that verdict but it was dismissed.
Appeal officer Simon Thomas, having heard from the player and his representative, found the suspension was not in error, and would stand.
