England coach Brian Ashton criticised his side's decision-making skills after their 26-19 defeat by Wales.
Ashton saw his side fall apart after an impressive first 40 minutes
The World Cup finalists let a 19-6 lead slip as they imploded on the opening weekend of the Six Nations.
"It is difficult to get my head around exactly what went on in the second half," Ashton told BBC Sport.
"A lack of clarity of thought and how to play under pressure cost us and we helped Wales along the way. We just didn't make correct decisions."
It was Wales' first victory at Twickenham in 20 years as they staged a remarkable comeback having looked out of the game at the break.
But second-half tries from Lee Byrne and Mike Phillips saw Warren Gatland begin his reign as Wales coach with a famous victory.
England's structure and game-plan, which had been so successful in the first half, went out of the window in the second period as the home side lost their way.
"They (Wales) didn't have to work particularly hard for their points," said Ashton.
"We said at half-time 'don't feed them the ball' and we fed them big-time. You don't just throw the ball around like that in international rugby."
Despite expressing his disappointment after the loss, England captain Phil Vickery urged his side to keep positive outlook for next week's game against Italy in Rome.
"We can't over-react," said the Wasps prop. "There were a lot of good things out there at times but also some pretty average stuff.
"People need to realise that there are going be rocky roads along the way and everyone has to understand that. We have to move forward next weekend in Italy."
England were hit hard by a bruising encounter, losing winger David Strettle, centre Mike Tindall and flankers Lewis Moody and Tom Rees to injuries.
Mike Tindall was one of the casualties in a hard-hitting game
But Leicester Tigers lock Ben Kay, who was compelled to play as substitute back-row forward, refused to blame their withdrawals, and the subsequent reshuffling of the positions, for his side's defeat.
"I think we lost the game because we made mistakes not because we had people in the wrong positions," he said.
"We just made errors and compounded those errors when we needed to get down into their half. There were three big errors and they seemed to come at a time that gave them such a big lift.
"Once they edged in front they did what we should have done. They kept hold of the ball, played their forwards round the corner and made sure that we couldn't get it back."
James Haskell, winning his third cap, was one of the few England players to end the game well.
The frustrated Wasps flanker said: "Playing rugby is based on basics and keeping things simple and effective. We didn't do that.
"One minute we were at one end of the field and the next minute we looked around and they had scored.
It's very annoying to let that game slip. But it's gone now - it's happened
"We need to make sure that we are a lot more ruthless.
"At times we showed how good we can be. But we didn't come together as well as we could do otherwise we would have got a victory if we had.
"We are going to go away and work extremely hard and turn those negatives into a positive."
Ian Balshaw, whose kick was charged down for Wales' winning try, said the World Cup finalists had been a "bit sloppy".
"It's very annoying to let that game slip. But it's gone now - it's happened," said the Gloucester full-back. "You have just got to move on. There's no point in dwelling on it."