The Reading striker, part of a sizeable contingent of Anglos at the Madjeski Stadium, was born in England but qualifies for Scotland via the grandparent rule and he looked the part with a first-half double which should really have provided a morale-boosting win ahead of next month's trip to Lithuania to take on Norway, Finland and the hosts.
"I thought we did exceptionally well," said Sbragia afterwards. "Harry is a handful up there, he is a young kid who has a lot to learn, but he is a goalscorer. That's why Reading paid money to take him from Hull."
This was as strong a squad as Sbragia could put out, with Celtic's Liam Henderson the man with most first-team experience in the group. But it soon became clear that Cardwell had some raw ability to go with his physique and fancy haircut. He latched on to a pinpoint cross from Celtic's Connor McManus to bullet a header into the top corner. Before long it was two, the big striker exhibiting calm to roll the ball beyond the Czech goalkeeper, Vojtech Vorel, from a Paul McMullan pass.
The Czechs had a beanpole frontman of their own, however, in the former of Sparta Prague's Patrick Schick, and he came up with a brace of close-range finishes of his own to bring matters level, the first coming on the stroke of half-time, the second halfway through the second period.
With both sides making a number of substitutions, Scotland should have scored the winner, with captain Scott McKenna spurning the best chance with his close range volley.