Calum Elliot grabbed the winner as Scotland booked a place against Spain in Saturday's final of the European Under-19 Championships.
Calum Elliot scored the vital goal for Scotland
The Hearts striker headed in off the post from 14 yards after a cut-back from Jamie Adams against the Czech Republic in Grodzisk Wielkopolski.
Scotland deserved their victory, with Steven Fletcher particularly dangerous.
But a booking for the Hibernian striker, who also went off injured, means he misses Saturday's final.
Archie Gemmill's Scots dominated the opening exchanges against the more-fancied Czechs.
Fletcher was put through on goal but stood on the ball with only the goalkeeper to beat.
The Hibs striker was then booked for simulation after stumbling under pressure from two defenders in the opposition box.
It appeared a harsh decision - especially as it meant he had to play on knowing he was out of the final.
Scotland were nearly caught on the break, but goalkeeper Andrew McNeill did well to turn a Martin Fenin volley from 16 yards over the bar.
McNeill's Czech counterpart, Radek Petr, did well at the other end to block at the feet of Michael McGlinchey after the midfielder was played through by Elliot.
Scotland's No.1 was fortunate to see a Marek Strestik header drift over after he failed to gather a cross.
A Fletcher free-kick was blocked clear by Petr, while McNeill followed suit to deny Fenin from close range after again failing to gather a cross.
A head injury forced Fletcher to be replaced with Robert Snodgrass at half-time.
And, within two minutes of the restart, Scotland were ahead, Elliot heading home off the far post after Adams had latched on to a free kick to direct the ball back into the danger area.
Petr Janda missed a great chance to equalise, driving the ball into the side netting from just six yards under pressure from McNeill after a goalmouth scramble.
McNeill was again on hand to block an effort from Marek Jungr from point-blank range.
But the Scots held on fairly comfortably to set-up a return match against tournament favourites Spain, who won the group meeting between the sides 4-0.
Javi García scored twice as Spain thrashed Austria 5-0 in the other semi-final, the other goals coming from Jeffrén Suárez, Juan Mata and Alberto Bueno.