Wales regained possession from the resulting re-start and, after a Scottish infringement at the ruck, kicked themselves back into the lead. The end-to-end action continued into the second half and Scotland were again in front when Weir slotted a penalty with 10 minutes to go, 17-16.
For the remainder of the game the Welsh, excellent around the breakdown, began to exert their strengths in the pack and powered across the line five minutes from time to win the match 21-17.
Scotland U17 head coach, Bryan Easson, said: "We're certainly not despondent. I’m very happy with the way the guys played, their offloading was good and their work in the contact area was excellent.
“This was the first part of a huge learning curve for the players. It’s the first international for all 26 squad players so it was quite a nervous experience for the 15 that started the match to begin with, but they got their shape and belief soon enough and showed what they can do."
Scotland next face Portugal on Thursday at 11.30am, Easson added: “Portugal are a good running side and have good ball handlers, they play a lot of sevens in Portugal and it shows.”
15 Harry Mountain (Gordonstoun)
14 Craig Robertson (Gala Wanderers)
13 Danny Gilmour (Stirling County)
12 Henry Oliver (Merchiston Castle School)
11 Jamie Anderson (George Heriot’s School)
10 Duncan Weir (Cambuslang)
9 Mark Clark (Annan)
1 Neil Kiltie (Robert Gordon’s College)
2 Richard Ferguson (Melrose Wasps)
3 George Hunter (Aberdeen Wanderers)
4 Luke Morrow (Merchiston Castle School)
5 Callum Evans (George Watson’s College)
6 Cameron Orr (Dumfries)
7 Duncan Finnie CAPTAIN (George Watson’s College)
8 Andrew Kirkland (Greenock Wanderers)