Wales coach Warren Gatland says his side made too many mistakes in their defeat by England at Twickenham.
Defending Six Nations champions Wales were beaten 29-18 by England, who lifted the Triple Crown for the first time since 2003.
Wales, who had won the Grand Slam in 2012 and the Six Nations title in 2013, saw their hopes of winning a third successive title end in London.
"It is disappointing because we didn't play well enough," said Gatland.
"We had too many turnovers, particularly in the first half. We didn't retain the ball for long enough periods.
"The two or three occasions we did retain the ball and we got behind them we created some chances that unfortunately we didn't finish off.
"The disappointing thing is that the turnovers were costly. The second try is from our line-out, close to our line. Those sort of things really hurt us."
Wales struggled in the first half, but went in 20-15 behind at half-time as Leigh Halfpenny's penalty kicking kept them in the game.
Halfpenny, who went off with a dislocated shoulder late on and will miss the rest of the season, scored all of Wales' 18 points with his boot.
Gatland paid tribute to the English performance and their first win over Wales in three games.
"They were a bit more accurate than us," said Gatland. "They defended incredibly aggressively and put us under pressure.
"I was just disappointed with the number of turnovers that happened and unfortunately at scrum-time we seemed to get on the wrong side of the penalty count which didn't help.
"I am not taking anything away from England and I thought they deserved to win the game."
Wales finish their Six Nations campaign on Saturday, 15 March against a Scotland side who have won only once in the tournament.
Gatland says he wants Wales to finish with a win against the Scots and keep their unbeaten home record in the this season's tournament after wins against Italy and France at the Millennium Stadium.
"It's a big one next week and means we would have won all our home games," he said.
"We want to finish with three home wins, having lost the two away, and we can get things back on track next week."