Colin O'Brien's side were a threat right from the off and led 3-0 at the break and went on to comfortably win the first of two friendly games against the Czechs in Co Tipperary this week.
Doubles from Adam Idah and Sean Brennan plus a late finish from Seanie Mahon sealed an emphatic victory for the home side, who had former international Keith Andrews with the team as an advisor.
Idah opened the scoring in the 17th minute when he peeled to the back post and got in an excellent header from Max Murphy's top class cross from the right.
In the 22th minute Ireland went 2-0 up when Idah lead a counter attack to run through and beat advancing keeper Adam Benada.
The third Irish goal was a real crowd pleaser as Sean Brennan scored with a fantastic flick from Callum Thompson's 37th minute corner.
Ireland's fourth goal in the 53rd minute was a brilliant combination that saw Idah lay the ball back for Sean Brennan to curl over the keeper with real confidence.
The Czechs pulled one back in the 60th minute when a shot by Matyáš Kozák deflected off an Irish defender to finally beat the impressive Kian Clarke in the Irish goal.
Mahon came off the bench to add Ireland's fifth goal with a brilliant counter-attack in the 76th minutes as outpaced the Czech defence before slotting past the keeper.
Kozák scored the Czechs second goal two minutes into injury-time when he finished from close range.
The sides will meet again at Cahir Park AFC on Wednesday (12.00 noon).
REPUBLIC OF IRELAND: Kian Clarke, Max Murphy, Ray O'Sullivan, Nathan Collins, Kameron Ledwidge, Adam O'Reilly, Barry Coffey, Sean Brennan, Callum Thompson, Adam Idah, Tyriek Wright. Subs:
Marc Walsh for Wright 58 mins; Jason Knight for O'Reilly 58; Ciaran Brennan for Coffey 72; Seanie Mahon for Idah 72.
CZECH REPUBLIC: Adam Benada, Michael Kavín, Tomáš Vincour, Šimon Gabriel, Ladislav Krobot, Jan Vokřínek, Marek Kostka, Vít Kolář, Ondřej Hapal, Matyáš Kozák, Claude Lhotecký. Subs: Marek Kejř for Hapal 55; Daniel Lojín for Lhotecký 55.