Williams scored in the 13th and 67th minute and sandwiched James Hook's second half try. Llanelli Scarlet Stephen Jones took over from Hook in the second half and his controlled style and accurate goal kicking helped to seal victory at the Millennium Stadium.

Scotland remained in the contest for more than an hour thanks to the boot of Chris Paterson which provided all of their points, but their hopes were dashed by Williams and a rejuvenated Wales side.

The hosts were given a heroes reception on their return to Cardiff following their historic triumph at Twickenham. Ryan Jones led his troops out in front of a Six Nations record crowd of 74,576.

Scotland's Chris Paterson became the visitors' most-capped back as the Gloucester wing made his 83rd appearance on his recall after Simon Webster's late withdrawal, but it was Wales who started brightly and held Scotland on their own try line within two minutes after flanker Martyn Williams and then Hook kicked on after Scotland hooker Ross Ford's poor line-out.

Wales peppered the visitors' line as Jones, Ian Evans and then Mike Phillips all surged for the opening score but Scotland held firm. Despite Wales's early domination, it was the visitors' who opened the scoring through Paterson's penalty on ten minutes. Wales hit back within two minutes as a sweeping move involving Gavin Henson, Hook and Lee Byrne found Williams who danced to score his 36th Test try.

Gatland's men were handed a further boost three minutes later when Scotland saw lock Nathan Hines yellow carded for a swinging arm on Byrne, but the hosts failed to capitalise on their numerical advantage as the visitors dug deep. Hook's penalty on 28 minutes increased their lead to seven points before Scotland suffered a big blow when skipper Jason White was replaced on the half hour by Allister Hogg.

Paterson kept Scotland in touch with his second penalty as Wales led 10-6 at the interval and Paterson reduced the lead to just one point with a third penalty on 44 minutes. Wales rallied and Hook scored Wales's second try two minutes later when he collected Duncan Jones's pass and accelerated through a gaping hole before handing off the challenge of Ford.

Paterson nudged Scotland back into contention with his fourth penalty and brought Frank Hadden's side back to 17-15 with his fifth successful kick on 55 minutes.

Gatland threw on experienced Llanelli Scarlets trio of Stephen Jones, Dwayne Peel and Matthew Rees for Hook, Phillips and Bennett and it worked a treat as Jones kicked Wales five points clear before Williams clinched the match with a brilliant solo try. He beat four Scottish challenges and then held off Ospreys team-mate Nikki Walker in the left corner. Italian Television match official Carlo Damasco awarded the try although it appeared his foot was in touch.

Jones added the conversion and his penalty with seven minutes left sealed an emphatic victory as Gatland's winning era continues.