Munster coach Johann van Graan said his side "had no excuses" after their thrilling Pro14 derby defeat to Leinster at Thomond Park.
The visitors were 27-5 ahead at the break and seemingly home and hosed.
Munster kicked back on the turnaround and threatened to pull off a stunning comeback but Jordan Larmour's brilliant individual try swung the momentum back in Leinster's favour.
It was a day of frustration for the men in red, and Van Graan admitted it was self-inflicted.
"It was not a good start," he told RTÉ Sport. "We spoke at half-time and said it could go either way: 'we could conceded 50 here, or stand up and fight'.
"We scored two tries very quickly and got back into the game. The 68th minute was a huge moment. We fought to within two yards of their line and conceded that penalty.
"We could have got to within one scoring opportunity with ten minutes to go. At the end of the day it's an 80-minute game. We weren't good enough for 40 and we paid for that."
Munster will now dust themselves down and go again at Ulster on New Year's Day. They sit in second in Conference A and will look for a more consistent overall display in their second derby clash in the space of a week.
"We'll learn from this, take it on the chin," Van Graan added.
"We were beaten by the better side. Well done to them.
"It's a learning experience for everybody including myself. I don't like to learn when I lose but that is when you've got to learn the most. It's a long season, this Pro14 competition.
"We were really looking forward to putting in a good 80-minute performance. Unfortunately we only put in a good 40. We've got no excuses."