Munster have suffered a 16-14 defeat away to Castres in the Investec Champions Cup meeting.
Munster scored two tries, with John Hodnett crossing over twice.
The French side had a 10-7 lead at the break, with Hodnett scoring his first try on the 37th minute to reduce the gap to three before the break
Munster lost Craig Casey and Peter O'Mahony to injury, but stayed in the game until the very end.
However, Jack Crowley's kick to touch from a penalty in the final moments failed to go out of play, in a disappointing night for the fly-half and his team in France.
While they will leave with a losing bonus-point, the win was there for the taking, in a frustrating display.
