Wales captain Sam Warburton admitted his team's discipline let them down as they were hammered 26-3 by Ireland in Dublin.
Man-of-the-match Peter O'Mahony destroyed Warburton at the breakdown, and Wales were smashed by a rampant Irish pack all afternoon.
The constant pressure led to the Welsh conceding 16 penalties, and there has been severe criticism of Wales' performance - former British & Irish Lions prop Graham Price called it "a crime" in his Wales on Sunday column.
"We knew we couldn't keep giving away penalties. We were talking about that, but couldn't change it," Warburton said.
"It was something we knew we had to correct, but we just couldn't do it. They made it very difficult for us over the ball. It was just execution from us, simple things like clearing rucks. We just weren't efficient there.
"They managed to slow our ball there, and they deserve a lot of credit. It was similar to what we experienced in the first-half last year against Ireland, but this time they maintained that for 80 minutes.
"I thought they were great against the All Blacks (last November), so we knew what was coming. But especially up-front - the breakdown, the maul, the lineout - they went better than us."
In his Sunday column Price wrote: "When you see the experience this team possesses, having been together for three years and achieved a Grand Slam and with Lions success behind them, I think that dire display was a crime and the players let themselves down.
"It's the worst performance I can remember in the Six Nations, especially when you consider what was at stake.
"It is not just the players who will have to take a look at themselves, because the coaches made mistakes with their substitutions, while there remain question marks whether they have an alternative or Plan B.
"Where this leaves Wales for the rest of the championship, I am not sure, because France and England are up next.
"They will have watched that game, and both sides will be confident on taking Wales on up-front. There is a lot to work on. And not much time to do it."