First-half tries by centre Tom Shanklin and lock Alun-Wyn Jones left the Scots reeling, before wing Leigh Halfpenny's touchdown just 48 seconds into the second period finished them off.
Wing Shane Williams' 45th Test try merely underlined Welsh supremacy, cranking up the pressure on Scotland coach Frank Hadden, whose team selection baffled many.
Scotland pressured late on and scored a consolation try courtesy of a fine effort from Max, which Chris Paterson converted following his two earlier penalties.
“I was told to go out and make an impact and that is just what I did,” said Max in The Times. “That is what I will always aim to do whether I am in the starting XV or joining the game off the bench. It was disappointing to come on in that position but there are positives we can take from that last quarter.”
The Glasgow centre told The Scotsman: "It is almost easier to come on when the team is behind than when the team is winning because you have nothing to lose and can just give everything.
"If you are winning, you have that little nagging in the back of your mind that you might let it slip for them. Don't get me wrong I would have loved to come on with Scotland winning, but the message was to go and really attack them, to get the ball early and have a go."
Things don't get any easier for Scotland with the trip to Paris looming.
Max said: "I'd love to start against France. I think France could be my kind of game if it is fast and open."