Irish had already lost three times to their hosts in domestic and European competitions this season, but two first-half tries from lock George Skivington helped the Exiles exact revenge.
Centre Steven Shingler added a penalty and conversion, while England international Freddie Burns booted four Gloucester penalties, yet Irish deserved a first Premiership away victory this season at the seventh attempt, which was sealed by full-back Tom Homer's late penalty.
It took them five points above bottom club Sale Sharks, who tackle Saracens on Sunday, and sent them into a five-week league break with renewed optimism of avoiding the drop.
In contrast, a losing bonus point was scant consolation for Gloucester after a four-month unbeaten home record disappeared.
- Sports & Recreation
- George Skivington