Scotland overcame a stunning fightback by Wales to end their 22-year wait for a win in Cardiff with a 27-26 victory in their Six Nations opener on Saturday.
The visitors were 27-0 up early in the second half only for the home side to score 26 unanswered points of their own.
Their nail-biting win meant Scotland ended a run of 11 straight defeats in the Welsh capital, a sequence including nine Six Nations losses.
Scotland were in command after Duhan van der Merwe went over for the second of his two tries, and his side's third in all after prop Pierre Schoeman crossed in the first half
But a new-look Wales, aided by a couple of Scotland yellow cards, then hit back with four tries as James Botham, grandson of England cricket great Ian Botham, Rio Dyer, impressive No 8 Aaron Wainwright and replacement Alex Mann all crossed to the delight of a raucous home crowd.
Scotland, for whom captain Finn Russell kicked three conversions and two penalties, were now clinging on to a one-point lead heading into the final 10 minutes.
But they regained their composure sufficiently to end the match by laying siege to the Wales line, with Van der Merwe being denied a hat-trick by the television match official.
"It's brilliant to win down here after not winning in Cardiff for 22 years but we will be a bit disappointed with that second-half performance," Russell told S4C.
"The second-half discipline wasn't good enough, two yellow cards allowed Wales back into the game."
Scotland next face France at Murrayfield, with fly-half Russell adding: "There is a lot of things to work on which is probably a good place to be getting a win first up down here."
Wales back-row Wainwright was left thinking of what might have been, telling the BBC: "We probably wanted the game to go on another five minutes.
"We left ourselves too much to do, and were probably not accurate enough in the first half."
- 'Shocking first half' -
Wales coach Warren Gatland added: "It was probably one of the worst performances, 40 minutes of rugby, in my whole career as a coach. It was terrible, we were shocking in the first half.
"There was nothing flashy about what was said at half time, it was go out there and play some rugby."
Wales were without a host of senior players due to injury and post World Cup international retirements, with winger Louis Rees-Zammit unavailable after opting for a career in American football
That lack of experience in a Wales team led by 21-year-old captain Dafydd Jenkins told in the first half.
It was Scotland who thrived first in under the Principality Stadium's closed roof.
Russell kicked an early penalty before his cut-out pass found Kyle Rowe and the full-back fed the ball inside to right winger Kyle Steyn before prop Schoeman forced his way over in the 10th minute for a converted try.
Russell extended Scotland's lead to 13 points with a penalty after Josh Adams deliberately threw the ball into the crowd to prevent a quick Scottish line-out throw.
Wales also didn't help their own cause with several knock-ons and over-thrown line-outs.
And they fell further behind when Russell sent in Van der Merwe in for a try between the posts on the half hour.
Scotland were 20-0 ahead and Wales suffered another setback when fly-half Sam Costelow went off after a clash of heads with Scotland flanker Luke Crosbie.
Costelow did not return for the second half after failing a head injury assessment.
Van der Merwe then scorched his way over for a fine solo try, with Russell's conversion making it 27-0.
But Gatland's trio of half-time changes - scrum-half Tomos Williams, hooker Elliot Dee and prop Keiron Assiratti -- helped galvanise Wales, who got on the scoreboard when Botham powered over crashed over.
George Turner was sin-binned for an offence in the build-up and Wales struck again through Dyer, with replacement Ioan Lloyd converting.
Sione Tuipulotu's yellow card frayed Scotland's nerves still further, with Wainwright powering over .
There was visible panic in the Scotland team when Mann went over but they just held out.