Tries from Rhys Carre and Josh Adams combined with Sam Costelow’s excellent kicking had given the hosts a well-earned 12-point lead at the break.

Costelow's second-half penalty then increased the Welsh advantage to 15 points, but three scores in the second 40 minutes from Finn Russell, Darcy Graham and George Turner turned the game on its head to give Scotland their second win of this year’s Championship and keep their hunt for a first title since 2000 alive.

Wales build momentum early on

Once the rousing renditions of the national anthems concluded, in which the home fans’ efforts when singing Mae Hen Wlad Fy Nhadau brough captain Dewi Lake to tears, a fierce Celtic clash ensued.

Scotland went close early on through Duhan van der Merwe, Huw Jones and Kyle Steyn but it was Wales, down to 14 after Joe Hawkins’ sin bin for a high tackle on Gregor Brown, who took the lead after nine minutes when Carre crashed over.

Costelow added the extras, but the visitors responded to Wales’ early blow through Steyn who had the simplest of walk-in tries in the corner after Scotland whipped the ball quickly from the left to right.

But just five minutes later, Wales extended their lead from two to nine points as Josh Adams' excellent early performance was rewarded with his second score of this year’s Guinness Men's Six Nations.

The wing dotted down in the corner after Costelow's brilliant kick got Wales up field before Eddie James, Carre and Alex Mann played instrumental roles in the build-up.

Costelow’s penalty gave Wales a 17-5 lead at the break, only their third half-time advantage at home in their last 18 attempts and their first under Stave Tandy, before the fly-half added a further three points eight minutes into the second half.

Trailing by more than two converted scores, Scotland had a gilt-edged chance to reduce their arrears, but Jones inexplicably failed to collect Van der Merwe's pass.

Scotland flip the script

But Gregor Townsend’s side remained undeterred and following a mammoth 27 phases, Finn Russell exploited Louis Rees-Zammit’s rush out from his defensive line to dive over.

Jarrod Evans, on for Costelow, notched up Wales’ third penalty of the match but the contest truly roared back into life moments later as the hosts were caught napping from the resulting kick-off.

Russell’s deep restart was collected, via a helpful bounce, by the ultra-aware Graham who had been on the field less than four minutes.

Scotland’s talismanic No. 10 slotted the conversion home to bring Scotland within four points with the score reading 23-19.

Crucial moments then failed to go the way of Wales thereafter as they looked to relieve the pressure Scotland were mounting on them.

Evans’ kick was just out of Rees-Zammit’s grasp before referee Matthew Carley reversed the penalty originally going to the hosts after Tomos Williams was penalised for a croc roll on Rory Darge.

And with six minutes left, Scotland completed their stunning turnaround and broke Welsh hearts as Turner was able to fall over the line from the back of maul following a driving lineout.

Russell again added the two and despite missing from the tee late on, Scotland held on to secure back-to-back wins and retain the Doddie Weir Cup.

Wales: 15. Louis Rees-Zammit; 14. Gabriel Hamer-Webb, 13. Eddie James, 12. Joe Hawkins, 11. Josh Adams; 10. Sam Costelow, 9. Tomos Williams; 1. Rhys Carre, 2. Dewi Lake (c), 3. Tomas Francis; 4. Dafydd Jenkins, 5. Ben Carter; 6. Taine Plumtree, 7. Alex Mann, 8. Aaron Wainwright

Replacements: 16. Ryan Elias, 17. Nicky Smith, 18. Archie Griffin, 19. Freddie Thomas, 20. James Botham, 21. Kieran Hardy, 22. Jarrod Evans, 23. Blair Murray

Scotland: 15. Blair Kinghorn; 14. Kyle Steyn, 13. Huw Jones, 12. Sione Tuipulotu (c), 11. Duhan van der Merwe; 10. Finn Russell, 9. Ben White; 1. Nathan McBeth, 2. Dave Cherry, 3. Zander Fagerson; 4. Max Williamson, 5. Scott Cummings; 6. Gregor Brown, 7. Rory Darge, 8. Matt Fagerson

Replacements: 16. George Turner, 17. Pierre Schoeman, 18. Elliot Millar Mills, 19. Grant Gilchrist, 20. Josh Bayliss, 21. George Horne, 22. Tom Jordan, 23. Darcy Graham