Colin O'Brien's side produced a competitive display to follow up on a 5-2 victory over the same opponents on Monday.
This time Jamine Nwanze was the only SKB starter with Kameron Ledwidge coming off the bench in the second half.
The Irish side got off to a solid start with wide-men Marc Walsh and Callum Thompson catching the eye. The home side should have taken the lead in the ninth minute when Seanie Mahon curled over brilliantly but defender Hakeem Ryan was unfortunate to see his effort bounce back away from goal from a matter of yards out.
Ireland's disappointment at that missed chance was eased less than 60 seconds later as they regained possession and Ciaran Brennan burst past the visiting defence to fire home brilliantly from the edge of the box.
The impressive Matyáš Kozák was again the Czech side's key danger in attack and in the 17th minute he got through on the left only to be denied at close range by Irish keeper Sam O'Gorman.
O'Gorman could do little to deny the Czechs an equaliser in the 29th minute when Vít KoláÅ™ found the net with a thumping free-kick from 25 yards out.
In the 47th minute Ireland were handed a golden opportunity to extend their lead when Tomáš Vincour was penalised for a foul on Ciaran Brennan after Formánek had initially denied the striker. After the dust settled Ciaran Brennan stepped up to fire home from the penalty spot.The drama dropped off a little after that but Ireland added a third in the 84th minute when Callum Thompson curled home brilliantly from a free-kick from 25 yards.
REPUBLIC OF IRELAND: Sam O'Gorman, Jamin Nwanze , Kevin O'Reilly , Oisin McEntee , Hakeem Ryan , Jason Knight, Seanie Mahon, Sean Brennan, Marc Walsh, Ciaran Brennan, Callum Thompson. Subs: Barry Coffey for S Brennan 60 mins; Kameron Ledwidge for Ryan 60; Adam O'Reilly for Mahon 69; Adam Idah for C Brennan 73; Tyriek Wright for Walsh 73; Max Murphy for Nwanze 77.
RESULTS
U15 Friendly Internationals
Monday, April 11
Republic of Ireland 5-2 Czech Republic, Clonmel Celtic FC
Wednesday, April 13
Republic of Ireland 3-1 Czech Republic, Cahir Park AFC