A first Champions Cup pool elimination for Munster since 2020, and more worryingly, a first elimination at this stage since the knockouts bloated to 16 teams.
The two-time winners suffered a final-quarter collapse as they fell to a 31-29 defeat to Castres Olympique, who pulled off a first ever win at Thomond Park in stunning fashion.
For head coach Clayton McMillan it's a rude awakening, with his side a shadow of the group which looked sensational against Leinster at Croke Park in November.
As sloppy as Munster were, they appeared to have wrestled control back on multiple occasions, which only makes this defeat sting further.
Craig Casey’s two first half tries saw them come from 10-0 down to lead 12-10, before they fell asleep just before half time to allow Castres retake the lead.
And it would be a similar story in the second half as Thaakir Abrahams and Edwin Edobgo crossed for a 24-17 advantage, only for a Tom Farrell yellow card to welcome the visitors in for their two winning scores.
It’s a habit the Munster head coach has become concerned with.
"The big disappointment for me and the worrying trend I guess is that we work really hard to score some points, but we give up points very quickly after scoring," McMillan (above) said of the defeat.
"We don't make it hard for opposition to have to come back and get points, and that's the one worrying trend for me over the last three or four weeks."
And the New Zealander admitted his side lost the game in "lots of different ways".
"There wasn't any one thing in particular," he continued.
"I think we missed a couple of kicks at goal. We fell off a few tackles. We created a few opportunities and didn't quite nail them. Missed a couple of lineouts.
"It's the accumulation of all the little things that make all the difference in the end. They hurt us.
"You win the game and they don't seem as important as when you lose, but that's the margins at this level if the game and games that have a lot riding on them. It's being on the right side of those moments. They had a few more than us."
In each of Munster’s three pool defeats, discipline has played a factor. Against Bath and Toulon they were punished with multiple tries while Tadhg Beirne was in the sin-bin, and both of Castres’ second half scores this evening came during Farrell’s yellow card.
"It's never a position you want to put yourself in," the head coach said of their final quarter.
"We talked about at half-time around, 'be urgent before you need to get desperate’.
"When it got out to nine points there late in the game, we saw an urgency about us and an accuracy about us that actually gave us an opportunity to get back in and score at the death and then give ourselves two minutes.
"I think in patches last week and this week I thought we played some of our better rugby, and especially attacking-wise created some opportunities, but just not nailing enough of them."
It could have been a heavier defeat had it not been for a couple of crucial breakdown interventions from their captain Tadhg Beirne.
And the skipper echoed his head coach’s thoughts that too many of their wounds were self inflicted.
"I felt like when we went ahead we were good, and then we just lost our way briefly," he said.
"We probably dug ourselves into a little hole for playing in our half a little bit at the point, but that had been working for us in the game so it's hard to go back and say we shouldn't have done that.
"We weren't switched on and we weren't good enough in those moments and they were able to exert more pressure onto us and capitalised on it.
"I think we'll be disappointed with our first half performance, defensively, for sure.
"We fell off too many tackles and just left them into the game that way, and then obviously a few penalties as well.
"I think attack-wise it felt like we were exploiting them quite well. It's just defensively, particularly in the first half, we just weren't where we needed to be unfortunately, and it was the losing of game really."
