Beck Cutting and Nick Rigby both started the encounter, while James Scott and Nick David came off the bench.
Wales led 14-0 at the break through converted tries from Tomi Lewis and Kemsley Mathias, and narrowly held onto that lead, despite two late tries from England’s Will Capon and a conversion from Cameron Redpath.
England next face South Africa Schools on Saturday 19 August at City Park, Athlone, in the final game of their tour.
England Under 18s
15 Ollie Hassell-Collins (London Irish, St Paul’s School)
14 Tom Seabrook (Gloucester Rugby, Dean Close School)
13 Cadan Murley (Harlequins, Bishop Wordsworth’s School)
12 Cameron Redpath (Sale Sharks, Sedbergh School)
11 Tom de Glanville (Bath Rugby, Beechen Cliff School)
10 Kieran Wilkinson (Sale Sharks, Kirkham Grammar School)
9 Ollie Fox (Yorkshire Carnegie , New College Pontefract)
1 George Head (Harlequins, Tonbridge School)
2 Beck Cutting (Worcester Warriors, Bromsgrove School)
3 Nick Rigby (Worcester Warriors, Warwick School)
4 Josh Basham London Irish, Wellington College)
5 Alex Coles Northampton Saints, The Perse School)
6 Richard Capstick (Exeter Chiefs, Exeter College)
7 Aaron Hinkley (Gloucester Rugby, St Peter’s High School)
8 Tom Willis (C) (Wasps, The Henley College)
Replacements
16 Tom Rowland (Bristol Rugby, Bristol Grammar School)
17 Will Capon (Bristol Rugby, Bristol Grammar School)
18 Joe Heyes (Leicester Tigers, Wyggeston & QEI College)
19 James Scott (Worcester Warriors, Malvern College)
20 Sam Moore (Sale Sharks, Sedbergh School)
21 Will Porter (Wasps, Merchant Taylors’ School)
22 Sam Spink (Wasps, Wellington College)
23 Nick David (Worcester Warriors, Warwick School)
MatchesÂ
Friday 11 August | England U18 24-8 France | Paul Roos Gymnasium, Stellenbosch
Tuesday 15 August | England U18 12-14 Wales | Paarl Gymnasium, Paarl
Saturday 19 August | England U18 vs SA Schools | City Park, Athlone (kick-off 1pm BST)