Dulwich College and Harlequins lock Twomey struck early in each half - from short and long range - with Harrow and London Wasps flanker Billy Vunipola adding England's third try and Whitgift and London Wasps centre Elliott Daly getting the fourth from the final move of the match
The shrewd game management of fly half Ford (Rishworth & Leicester Tigers), who added four conversions and five penalties for a 23 point return, did the rest and extended England's winning run to 16 successive international victories at this level since 2007.
The scoreline was harsh on a talented Wales side who attacked them with relish. Scarlets centre Luke Williams scored their first half try and Ospreys fly half Matthew Morgan kicked a conversion and five penalties to keep them in touch until Ford and Daly delivered the coup de grace.
England had made a supercharged start with a sweeping attack with Marland Yarde (Whitgift & London Irish) involved twice only for them to lose the ball on the line. They won it back immediately, forcing a penalty at the next scrum with Twomey powering his way over from the lineout that followed.
Ford converted from the right-hand touchline but England couldn't add to the early score against a lively Wales side containing Tom Prydie at full back, eight days after his high-profile RBS 6 Nations debut against Italy.
Morgan got Wales on the board with a penalty after 20 minutes then added the conversion after his side were rewarded for some ambitious offloading as their back row attacked and created space for Scarlets centre Williams to get outside his marker and over the line.
They dominated territory after that, too, with Morgan adding a second penalty on the stroke of half time when England stepped offside at a lineout 30 metres out.
Another penalty immediately after the break - killing the ball on the edge of their own 22 - enabled Morgan to make it 16-7 and England needing to get back into the game quickly.
They did so from a lineout drive with Ryan Mills (Hartpury & Gloucester) offloading out of the tackle to stretch Wales down the left before the ball came back for Twomey to breeze through a gaping midfield gap with Ford adding the extra points.
England's third try followed another driven lineout 30 metres out, Ford's floated delivery allowing Vunipola to blast through a half-hearted tackle and dive over under the posts.
Ford converted and then added a long-range penalty, but two more Morgan penalties kept Wales within two points and playing against 14 men after Matt Kvesic was sent to the sin bin.
Ford eased any pressure, though, with four more penalties inside the last 15 minutes and then converted Daly's late try to complete a faultless nine out of nine shots at goal.
Wales Under 18:
Tom Prydie (Ospreys); Harry Robinson (Blues), George North (Scarlets), Luke Williams (Scarlets), Eli Walker (Ospreys); Matthew Morgan (Ospreys), Jonathan Evans (Dragons); Daan Harris (Blues), Kirby Myhill (Scarlets), Will Griff John (Blues), Cory Hill (Blues), Luke Hamilton (Scarlets), Owen Sheppeard (Blues), Thomas Young (Blues, Captain), Dan Baker (Ospreys).
Jack Dando (Blues) for Myhill 54, Rob Evans (Scarlets) for Harris 47, Samson Lee (Scarlets) for John 52, Matthew Screech (Blues) for Baker 66, Ellis Jenkins (Blues) for Sheppeard 54, Tom Habberfield (Ospreys) for Evans 54, Joseff Griffin (Blues) for Morgan 68, Sam Campbell (Blues) for Robinson 68.
Scorers: Try: Williams. Conversion: Morgan. Penalties: Morgan 5.
England Under 18:
Ben Ransom (Tonbridge & Saracens); Marland Yarde (Whitgift & London Irish), Elliot Daly (Whitgift & London Wasps), Ryan Mills (Hartpury Coll & Gloucester), Charlie Walker (Oakham); George Ford (Rishworth & Leicester Tigers, Captain), Joel Hodgson (RGS Newcastle & Newcastle Falcons); Nick Auterac (Oaklands College & Saracens), Koree Britton (Ivybridge Coll & Exeter Chiefs), Anthony Brennan (Twyford CofE & London Wasps), Dominic Barrow (Prince Henry's GS Otley & Leeds Carnegie), Sam Twomey (Dulwich Coll & Harlequins), Billy Vunipola (Harrow & London Wasps), Will Skuse (Bryanston & Bath Rugby), Matt Kvesic (Worcester Sixth Form Coll & Worcester Warriors)
Nathan Moris (Sedbergh & Newcastle Falcons) for Britton 60, Luke Cowan-Dickie (Truro Coll & Exeter Chiefs) for Auterac 41, Kyle Sinckler (Epsom Coll & Harlequins) for Brennan 68, George Merrick (Whitgift & Harlequins) for Barrow 68, Dan Robson (Hartpury Coll & Gloucester Rugby) for Hodgson 52, Chris Elder (RGS High Wycombe & London Wasps) for Yarde 68, Mark Jennings (Lymm HS & Sale Sharks) for Charlie Walker 54.
Scorers: Tries: Twomey 2, Vunipola, Daly. Conversions: Ford 4. Penalties: Ford 5.
England Under 18 2009/10
December 13: England U18 30 Australia Schools 28
February 21: England U18 33 France 16
March 6: Italy U18 12 England U18 28
March 28: Wales U18 22 England U18 43
April 2: England U18 v Ireland (Llandovery, 4pm)
April 6: England U18 v Scotland (Llandovery 2pm)
Content courtesy of RFU