Goals on their full Ireland debuts for Matthew Murray and Charlie Hamilton got Ireland on their way before Bez Agbontaen made it 3-0 before half time.
Two goals from Darragh Marshall and another from Christian Donlon-Goncalves gave Jason Donohue's side an impressive victory in their second game in two days.
Having drawn against Montenegro 0-0 yesterday, despite their possession, Ireland were determined to get three points on the board. And in the 14th minute they were ahead when Cork City's Murray was able to score on the rebound from a Afi Adebayo shot.
Eight minutes later Ireland doubled their lead and Adebayo was involved again when he crossed from the left and St. Patrick's Athletic forward Hamilton volleyed home for 2-0.
Just before half-time Hamilton was brought down for a penalty and it was his club mate Agbontaen who stepped up to give Ireland a commanding lead at the break.
Shortly after half-time it would be another penalty for the young Boys in Green, this time the man to convert it was Darragh Marshall as Ireland went 4-0 ahead.
It was 5-0 in the 51st minute when Kyle Fitzgerald stole possession, drive down the left and played it across goal for Donlon-Goncalves to score.
Shamrock's Rovers' Donlon Goncalves was heavily involved in the sixth when he led a counter attack, drove into the box and fired at the goalkeeper who made the save but couldn't deny Marshall his second of the game to make it 6-0.
Ireland MU15s are back in action tomorrow when they take on the hosts Croatia. A win will see Ireland make Sunday's final.
Republic of Ireland: Collins, Rabbette (Harnett, 67), Coffey (Graminschii, 56), Lillis, Kizenga (Roche, 67), McAndrew (Sean Moore, 67), O'Donnell (Chan, 67), Murray (Fitzgerald, 43), Adebayo (Donlon-Goncalves, 41), Agbontaen (Marshall, 41), Hamilton (Schutte, 41)
Uzebekistan: Mamatov, Shorakhmedov, Abdukhakimov, Abrorov, Ermanov, Abraev, Agaev, Akhmadov, Yunusov, Olimov.
Susbtitutes: Erkinzoda, Akramov, Pulatov, Khudaybergenov, Khabibullaev, Tadjiev, Nazarov, Eschmamatov, Maratov, Nematbekov, Muratbekov, Mutalov
Referee: Jasmin Horvat (Croatia)
International MU15 friendly fixtures (all times are Irish time)
Friday, May 13 | Croatia MU15 v Republic of Ireland MU15, Varazdin Stadium, Croatia, 11am
Sunday, May 15 | Republic of Ireland MU15 v TBC, Play-Offs/Final, TBC