Vaclav Kadlec scored the only goal of the game as the Czech Republic beat Wales in a Uefa Under-21 Championship qualifier.
Kadlec scored with a free header after 5 minutes following Vladmir Darida's corner.
Ryan Doble and Tom Bradshaw went close for Wales although keeper Chris Maxwell was also kept busy at the other end.
Troy Brown and Lee Lucas both had late efforts but Brian Flynn's side fell to their second defeat of the campaign.
The defeat leaves Wales fourth in Group Three halfway through their qualifying campaign, a point behind the Czechs and Armenia, who both have a game in hand.
Wales U21: Maxwell, Freeman, Richards, Lucas, Brown, Alfei, Jake Taylor (Bodin 46), Hewitt, Bradshaw (Ogleby 74), Doble (Chamberlain 66), Howells. Subs Not Used: Cornell, Evans, Dummett, Stephens.
Booked: Richards, Alfei
Czech Rep U21: Stech, Lecjaks, Hejda, Kalas, Nitriansky, Kopic (Cmovs 90), Krejci, Darida (Marecek 78), Nespor (Chramosta 68), Kadlec, Hanousek. Subs Not Used: Vales, Husbauer, Navratil, Novak.
Booked: Hejda, Nespor
Goals: Kadlec 5
Ref: Nikoloj Hanni (Switzerland)