England won their World Cup dress rehearsal against Wales by getting their RBS 6 Nations off to a perfect start with a 21-16 victory at the Millennium Stadium.

Wales took a 10-0 lead inside eight minutes, with Rhys Webb scoring the game's first try, and led 16-8 at the interval.

But Bath pair Anthony Watson and Jonathan Joseph both grabbed tries as England shut out Wales in the second half and won for the first time in Cardiff after trailing at the break.

The roof was open after England had declined an offer to have it closed and Wales immediately looked as if they had been angered by the decision.

The Welshmen won their own kick-off and, when the ball was switched back to the right, they won a penalty which the ever-reliable Leigh Halfpenny landed from 40 metres.

There was even better to come for the home team after eight minutes when Dan Biggar's cross-field kick found Halfpenny on the touch-line and the full-back chipped on to cause panic on the England line after Anthony Watson had gathered.

Wales were given the scrum and, even though it was going backwards, Toby Faletau picked up and shrugged off the tackle of James Haskell to slip in Rhys Webb at the corner.

Halfpenny converted for a 10-0 lead but England hit back after 15 minutes when pressure at the scrum set up territory and Mike Brown chipped through for Watson to collect his first Test try, George Ford striking the upright with his conversion attempt.

Wales were keen to test Ford's defensive abilities at every opportunity and send powerhouses Jamie Roberts and Alex Cuthbert down his channel, but England were not giving an inch despite having come into the game as underdogs.

Halfpenny then landed another 40-metre penalty after England prop Dan Cole was penalised for going off his feet at a ruck.

Ford replied with a penalty of his own after Roberts was penalised for an early tackle on Jonny May and Wales lost George North in the same passage of play as the winger was caught by the flying boot of Dave Attwood.

North was back on the field just before the break and Biggar's 35-metre drop goal extended Wales' lead with the final kick of the first half.

England started the second half on the front foot and they were rewarded for their patience inside four minutes as they went through 20 phases before Joseph slipped Biggar and North to burst over the line, Ford's conversion making it a one-point game at 16-15.

Wales were struggling to combat England's positive approach but Ford spurned the opportunity to give the visitors the lead when his penalty attempt missed the target from 45 metres.

Roberts on the crash ball tried to give Wales some momentum and lift a home crowd who had been expecting an easier evening against injury-ravaged opponents.

But England managed to turn the ball over in their own 22 and lift the pressure as the tempo paused for breath as Halfpenny required treatment following a bang on the head.

England were making the most of their advantage in the scrum to enjoy good territory and Ford's penalty put the visitors ahead at 18-16 with Cuthbert yellow carded to reduce Wales to 14 men on the hour mark.

Wales did not concede when Cuthbert was off the field but England might have put the game to bed when centre Luther Burrell broke clear in open play.

Brown had clear grass to run into but Burrell's pass was slightly high and behind him and the full-back was unable to hold on.

England were denied a third try when Attwood's effort was disallowed for replacement Nick Easter blocking Biggar but Ford's 45-metre penalty two minutes from time settled matters.