Brendan Venter lost his appeal against his 14-week ban but it was reduced by four weeks.
The Saracens director of rugby was found guilty of conduct prejudicial to the interests of the game after an incident involving spectators during a match against Leicester earlier this month.
The original RFU ruling said Venter waved and blew kisses in the direction of Leicester supporters who were calling at him to sit down as he was blocking their view of the action. There were also allegations that he swore at the spectators.
Venter was slapped with a 14-match ban, which will not allow him to attend the English Premiership final against Leicester on Saturday. Saracens appealed the ban on Wednesday, but the RFU denied their appeal and only reduced the ban to 10 weeks, until the 29 July.