The star wing insists Wales forwards out-gunned their feared opponents in the 50-44 opening defeat by the Pumas in Tucuman.

But he also saw the visitors hopes crumble amid a strange opening to the second-half in which Wales conceded three tries in seven minutes.

Williams said: Our concentration lets us down and we were not expecting what Argentina might bring, especially in the second half.

We had a really odd first few minutes of the second period. Argentina hadnt shown any kind of attacking football in the first-half and we had not shown how badly we can defend at times.

Those first few minutes of the second period added up to something a bit different from both sides and it killed us.

Williams believes the collapse was all the stranger because the Welsh pack had easily done enough to suggest he and his team-mates were more than a match for their hosts.

But Williams says Wales wasted their chances through a combination of Argentinian street-wisdom and a lack of application to the games finer points by the tourists.

Williams said: It was hard because at times we had so many numbers out wide and chances to score, especially out on the wing.

But they didnt come because the Pumas spoiled our attacks or because of knock-ons. That was tough and frustrating because at those moments you have to be confident you can score.