Sionko almost had a second goal in the 29th minute when goalkeeper Ricardo flapped at another corner, but Joao Moutinho cleared his header off the line.
The Czechs battled bravely for an equalizer, but Sionko saw his 83rd-minute header tipped over by Ricardo from yet another set-piece when it seemed he should have scored.
With his side showing no sign of a breakthrough, Le Guen resorted to a double substitution, with Kris Boyd and Chris Burke replacing Dado Prso and Libor Sionko.
Cech then denied Simao Sabrosa, and at the other end Tomas Ujfalusi's header flashed past the past from another corner with Sionko and Milan Baros both just failing to make a vital connection.
Chelsea stopper Cech reacted quickly to push David Rozehnal's wayward header round the post but the Czechs broke quickly from the resulting corner, only for Libor Sionko to hit a weak shot which was easily saved by Taylor.