Wales ended up well beaten despite a battling performance in this European Championship qualifier.
Germany took the lead when Sahr Senesi latched on to a long ball from Moritz Volz and powered his shot into the roof of the net from a narrow angle.
Alexander Ludwig made it 2-0 when his low long-range drive into the corner beat Wales keeper Lewis Price.
Wales fought on but Mike Hanke smashed home Germany's third goal and Marcell Jansen added a fourth late on.
Wales, watched by senior national boss John Toshack, started with a 4-2-3-1 formation that is believed to be the one that will be used by the full team against Hungary on Wednesday.
Germany controlled possession from the off but Wales held their own in the opening minutes and Richard Duffy's lobbed through-ball almost set up David Vaughan for the home team.
But Brian Flynn's side fell behind on 15 minutes when James Collins failed to deal with a ball from Volz down the right flank and Senesi raced in to fire a powerful shot past Price.
The Germans should have made it 2-0 soon after when Hanke prodded a tame shot into Price's hands after a neat build-up.
Wales continued to battle however, and some good work on the left from Ramon Caliste set Peter Gilbert free in the box, but the full-back's tame shot trickled wide.
And the visitors' second goal arrived on 25 minutes when Ludwig was allowed to advance before beating Price with a speculative low shot into the corner from outside the area.
Wales problems increased on the half hour mark when James Collins was stretchered off with an ankle injury.
The Cardiff centre-back was left out of the senior squad specifically to lead the Welsh backline here but it became clear he could not continue.
Despite that setback Wales fought on and they were a much-improved side after the break.
Their best chance was a Joe Ledley header that looped just wide on 56 minutes.
That was their only clear-cut opportunity but their passing and movement was enough to keep the Germans subdued.
But the visitors always looked capable of upping the ante again, and they did so in the closing stages of the game.
On 79 minutes it was 3-0 when Hanke made a strong run into the box and unleashed a powerful shot which flew into the far corner of the net.
And when a loose ball broke to Jansen on the edge of the area in injury time he fired home a first-time shot which took a slight deflection on its way past Price.
The win puts Germany ahead of England at the top of Group Six on goal difference.
Wales Under-21: Lewis Price (Ipswich Town), Richard Duffy (Portsmouth), Peter Gilbert (Plymouth Argyle), David Pipe (Notts County), Craig Morgan (Wrexham), James Collins (Cardiff City, capt), Andrew Crofts (Gillingham), Lee Fowler (Huddersfield Town), Ramon Caliste (Manchester United), David Vaughan (Crewe Alexandra), Joe Ledley (Cardiff City).
Subs: Lee Jon Beevers (Boston United), Lewin Nyatanga (Derby County), Anthony Pulis (Stoke City), Jamie Tolley (Shrewsbury Town), Craig Davies (Oxford United), Stuart Fleetwood (Cardiff City), Lee Worgan (Rushden & Diamonds).