Owen Williams and Robin Copeland both scored their first tries for the Cardiff Blues as they floored Munster 17-6 at a foggy Musgrave Park.
It was the Blues' first win on Munster soil since October 2007 and occurred on a night when Ronan O'Gara became the Irish province's most-capped player.
O'Gara will not want to remember his 233rd competitive appearance as he was outshone by his opposite number, man-of-the-match Rhys Patchell.
The 19-year-old Patchell converted both tries, adding to an early penalty, and displayed a calmness and control beyond his years in the number 10 channel. O'Gara kicked a penalty in each half but Munster lacked penetration throughout and have now fallen to sixth in the RaboDirect PRO12 standings.