Giorgi had upset home favorite and top seed Agnieszka Radwanska in the semi-finals and was favorite for the final, but she failed to live up to her previous heroics.
The Italian also fell at the final hurdle in the Polish city last year when she squandered a match point against France’s Alize Cornet.
World No 67 Schmiedlova recovered from an early break of serve to win four straight games, clinching the first set in 47 minutes. She also battled back from behind in the second set.
Her only previous final had ended in defeat against an Italian opponent – Sara Errani – at the Rio Open earlier this year.