Wales Women's late 15-14 Women's Six Nations defeat by Scotland Women was a "disgrace" according to head coach Rowland Phillips.
Carys Phillips crossed over for the visitors, who led 14-7 at half time but saw Sarah Law's late penalty give the Scots a famous victory in Cumbernauld.
The win was Scotland Women's first in the Women's Six Nations since 2010.
"Our scrum looked superior, our line-outs were good, but discipline let us down," Phillips told BBC Wales Sport.
"It was a disgrace the way we played. Having got into a 14-0 lead [in the first half] and been very much in control, we just didn't show the discipline you need not just to win international games, but to win a game of rugby.
The result drew Scotland level on five points in the 2017 Women's Six Nations table and Phillips was unhappy with how his side dealt with Scotland's counterattack.
"Unfortunately we buckled under the pressure," he continued.
"We know they [Scotland] have improved and we commend them on the result, I mean that. But everything that happened was down to our failings to actually control ourselves around the ruck area.
"Well done to Scotland, it was pretty basic what they were doing but it was effective.
"We'll have to have a look at the game because the discipline side of our game is totally unacceptable."