Tom Youngs forced his way over in the final seconds
Wales U20: (12) 21
Pens: Priestland (7)
England U20: (6) 21
Tries: Doherty, Youngs
Pens: Cozens (3)
Tom Youngs' converted try nine minutes into second-half stoppage time snatched a draw for England at Rodney Parade.
Four Rhys Priestland penalties to two from Luke Cozens gave dominant Wales a 12-6 half-time lead.
David Doherty's try shortly after the break brought England to within a point as Cozens missed the easy conversion.
Priestland took Wales clear with three penalties in quick succession, but Cozen hit a penalty and then converted wing Youngs' try to level the scores.
England, who had won two of their previous four games this season, piled on the pressure in the final stages and finally broke through the Wales defence with a simple midfield move as the clock reached 89 minutes.
Wales' best try-scoring opportunity came in the first-half when full-back Martyn Thomas made the most of a favourable bounce to put Jimmy Norris clear.
The winger had the tryline in his sights, but England full-back arrived at the nick of time to bundle him into touch.
England number eight Hugo Ellis suffered the same fate after breaking from the base of the scrum 40 metres out just before the break.
Ellis had Doherty on his inside shoulder, but his decision to go for the corner instead of cutting inside meant the winger had no room to manoeuvre.
The result meant England finished third behind Ireland, who clinched the Grand Slam, and France.
Wales, whose only victory came against Scotland, finished fifth.
Wales U20: Martyn Thomas (Dragons); Alec Jenkins (Llanelli / Scarlets), James Lewis (Bedwas / Dragons), Gareth Maule (Newport / Dragons), Jimmy Norris (Bedwas / Dragons); Rhys Priestland (Llanelli / Scarlets); Robert Lewis (Neath / Ospreys); Hugh Gustafson (Llanelli / Scarlets, capt), Marc Jones (Sale Sharks), Jamie Corsi (Newport / Dragons), Bradley Davies (Blues), James Down (Cardiff / Blues), Danny Lydiate (Ebbw Vale / Dragons), James Harris (Bedwas / Dragons), Lewis Evans (Newport / Dragons).
Replacements: Ken Owens (Llanelli / Scarlets), Nick Eaves (Pontypridd / Blues), Adam Brown (Bedwas/Dragons), Matthew Larsen (Cardiff / Blues), Darren Allinson (Cardiff/Blues), Rhys Jones (Sale Sharks), Luke Ford (Wanderers / Blues).
England U20: David Smith (Northampton Saints); David Doherty (London Wasps), Dominic Waldouck (London Wasps), Adam Powell (Saracens), Tom Youngs (Leicester Tigers); Luke Cozens (Bath Rugby), Danny Care (NEC Harlequins, capt); Dan Cole (Leicester Tigers), Matt Mullan (Worcester Warriors), Tom Mercey (Saracens), Dave Attwood (Bristol Rugby), Phil Hoy (Northampton Saints), Alex Shaw (Leicester Tigers), Andy Saull (Saracens), Hugo Ellis (London Wasps).
Replacements: Ross McMillan (Gloucester Rugby), Charlie Beech (Northampton Saints), Chevvy Pennycook (Bristol Rugby), Matt Cox (Worcester Warriors), Danny Pointon (Northampton Saints), Ollie Dodge (Leicester Tigers), Ben Thomas (Saracens).