The sides had been level at 3-3 after a scrappy first half but Wales clicked into gear early in the second period to kill off a Scotland side who again paid for a lack of composure.
Scrum-half Chris Cusiter’s failure to gather Rhys Priestland’s second-half kick-off sparked Scotland’s implosion as it laid the platform for wing Alex Cuthbert to score the opening try, converted by Leigh Halfpenny.
Full-back Halfpenny, who ended the game with 22 points, then added his second penalty and two converted tries to punish Scottish ill-discipline as Nick De Luca and Rory Lamont saw yellow, effectively killing the game off with the score at 27-6 after three Welsh tries in 14 minutes.
Wales managed the victory despite having captain Sam Warburton ruled out before kick-off with the dead leg he suffered in Dublin last week, and lock Bradley Davies suspended following his tip tackle in the same game.
And it was his side’s ability to deal with those obstacles that pleased Gatland most.
He said: “We expected Scotland to be a lot tougher than maybe the public did.
“If you look at their numbers last week in terms of territory, possession and line breaks, they should have won that game against England.
“So we are very pleased with the result given the disruption of losing Sam Warburton, and having to adjust to the loss of Bradley Davies during the week, as well as being without three or four key players.”
Scarlets flanker Aaron Shingler, whose brother Steven is at the centre of an eligibility row after being named in Scotland’s Six Nations squad, was handed the task of filling the boots of the talismanic Warburton, and produced a solid display to mark his first cap.
And Gatland praised the back-rower’s contribution.
“He had a good game, he made a couple of good carries,” he said. “There was a moment in the second half after we had scored where he probably should have passed, but he took ball into contact and got turned over and conceded a penalty.”
Wales also picked up injury problems during the game as wing George North and hooker Huw Bennett were forced off with ankle and calf problems respectively.
But Gatland is hopeful of having the giant North available when his side go for a clean sweep of the home unions at Twickenham, and expects to have a handful of other players back.
Scotland boss Robinson refused to criticise his side.
“The guys did not deliberately get sin-binned, but that’s what happens in the game. Wales exploited the space really well and kept hold of the ball,’’ he said.
“When you are down to 13 men you are going to be put under pressure if a side is able to keep hold of the ball and keep a good shape and I thought they did that really well.”
Scorers for Wales: Tries: Cuthbert, Halfpenny 2. Cons: Halfpenny 3. Pens: Halfpenny 2.
Scorers for Scotland: Tries: Laidlaw. Cons: Laidlaw. Pens: Laidlaw 2.
WALES: Halfpenny, Cuthbert, J. Davies, Roberts, North, Priestland, Phillips, Jenkins, Bennett, A. Jones, R. Jones, Evans, Lydiate, Warburton, Faletau.
Replacements: S. Williams for Roberts (77), Hook for North (39), L. Williams for Phillips (74), Owens for Bennett (40), James for A. Jones (72), Reed for R. Jones (74), Powell for Lydiate (72). Sin Bin: Jenkins (77).
SCOTLAND: R. Lamont, Jones, De Luca, S. Lamont, Evans, Laidlaw, Cusiter, Jacobsen, Ford, Cross, Gray, Hamilton, Strokosch, Rennie, Denton.
Replacements: Blair for Cusiter (48), S. Lawson for Ford (71), Kalman for Cross (57), Kellock for Hamilton (57), Barclay for Strokosch (44).
Referee: Romain Poite (France).