A Chesterfield clubber was jailed after he groped and rubbed himself against a woman at a town centre nightclub.
CCTV footage from the Association nightclub on Corporation Street show Anbesajer Zeraey, 31, manoeuvring his victim round the dancefloor.
He also slapped her bottom, grabbed her from behind so she couldn’t move her arms and ground his groin against her.
She was then assaulted in ‘a dark corner’ of the club by another man, who put his hand up her skirt.
After the incident took place, Zeraey was ejected from the premises, the court heard.
Zeraey was later arrested and convicted of sexual assault on the basis of images taken from the club’s CCTV cameras.
He was jailed for eight months at Derby Crown Court in December last year.
But now judges at London’s Criminal Appeal Court have halved his sentence to four months.
He ought not have been linked to another sex attack on the same victim by another man in the club that night, they ruled.
Zeraey’s lawyers argued that the judge had wrongly sentenced him on the basis that he acted in concert with others.
The prosecution had not alleged that that was the case.
Allowing the appeal, Lord Justice Hamblen said: “The offending included an element of public humiliation which justified immediate custody, but it didn’t justify a sentence of this length.”