Wales, and boss Warren Gatland, had been under pressure heading into the match having failed to win any of their previous eight fixtures but Williams ensured that record was impressively ended at Murrayfield.

Williams' two scores - one early in the first and the other late in the second - and 14 points from the boot of fly-half No. 10 James Hook did the damage as Wales made light work of an off-colour Scottish side.

Dan Parks kicked six points for the home side but they were ultimately made to pay for some sloppy errors and failing to take any advantage when Wales were reduced to 13 men after two sin-binnings in the first half.

Wales succeeded where they had failed a week previously against England by making the most of some early chances to get on the scoreboard.

The stuttering attacking from the England clash was a distant memory as Williams crossed after eight minutes to open the scoring.

Hook - replacing Stephen Jones at No. 10 - made the decisive break and offloaded to the Ospreys wing for the 33-year-old's 52nd try in the Welsh jersey.

Having created the try Hook added the comfortable extras from under the posts and Gatland's men had a 7-0 lead.

Five minutes later the visitors were ten points to the good when Scotland strayed offside and Hook kicked the resulting penalty.

Wales continued to dominate proceedings and earned themselves another three points - to make it 13-0 - when Ross Ford was penalised for coming into the side of a ruck and Hook duly slotted over.

Scotland might have been down to 14 midway through the half when Hugo Southwell tackled Welsh full-back Lee Byrne in the air but the home full-back was spared the sin-bin.

Southwell was forced off the field with blood streaming from his face but Wales felt the he should have been leaving for differing reasons.

On 21 minutes Wales' perfect start continued when Hook kicked his 11th point of a near-flawless first half after yet another Scottish infringement.

The home side were handed a lifeline two minutes later when Bradley Davies was sent to the sin bin for cynically disrupting a flowing Scottish move with his boot.

And on 26 minutes Wales were down to 13 when Jamie Roberts went the same way as Davies - yellow-carded for a high tackle on Max Evans.

However despite their numerical superiority the home side contrived to waste their advantage - showing a criminal lack of composure to rack up just three points in the remainder of the half through a Dan Parks penalty.

Their struggles - which were not helped by some heroic Welsh defending - were summed up right on the half-time whistle when Parks slipped while striking a shot at goal to leave the welsh 13 points to the good at the interval.

Wales - and Hook - had the first chance to trouble the scorers after the interval when the Scottish scrum buckled on 46 minutes but the France-bound utility back's long-distance penalty didn't have the legs.

Scotland got themselves to within ten points when Parks kicked his second penalty on 57 minutes.

And they might have been within touching distance heading into the last 20 minutes but Andy Robinson's men contrived to waste two inviting overlaps.

But it was Wales who grabbed the next points with another Hook penalty - his last action before being replaced by Jones.

Gatland's side could have been celebrating their second score of the game with Jamie Roberts bearing down on the try line after Scotland had contrived to lose possession on the half-way line.

The Blues centre was hauled back Sean Lamont but minutes later Scotland infringed again and Hook made it 19-6.

The game was finished 11 minutes from time when Williams added his second of the day after yet more sloppy Scottish play on the half-way line.

Nikki Walker's pass went astray and Williams dashed onto a Jonathan Davies kick ahead for his 53rd try of his international career.

Jones missed the conversion but it didn't matter as Wales grabbed their first win in nine games to get their Six Nations campaign back on track.