Dave Connell asked his team to do all that they could to pick up the three points after drawing 1-1 with hosts Slovenia on Tuesday and they certainly did that with a deserved win.
Megan Connolly netted four times - bringing her tally to five from two games - while captain Savannah McCarthy and winger Jessica Nolan got one apiece to leave Ireland second in Group 10 behind leaders Russia.
"We passed the ball a lot better today. We had a lot of chances on Tuesday against Slovenia, but we converted them today and we were very dominant overall," said Connell.
"We came out with the intention of topping our group. We knew that it wouldn't be easy and we wanted to respond from the draw with Slovenia and we did that by picking up the win.
"We made two changes for this game and all of the girls put in big performances. We're happy with how they played and we'll look forward to playing Russia on Sunday and finishing on a high."
Connolly opened the scoring for Ireland after just nine minutes, showing her class to execute in an early stage of the game, and McCarthy followed it up with a goal of her own on 12 minutes.
The chemistry between the two was evident throughout, especially when Connell moved McCarthy further forward, and the goals kept on coming with Connolly notching in three more - including one from the penalty spot.
Nolan fired in as well to showcase the spread of quality in this Ireland squad and they will look to match that with their confidence as they prepare to take on Russia on Sunday in what will be a battle to top the group.
Republic of Ireland: Dunne; Donnelly, Keenan, Moloney, McCartan; H Nolan (Byrne 65), Daly, McCarthy; Finn (Watters 54), Connolly, J Nolan (McLaughlin 75).
Bulgaria: Kalcheva; K Georgiva, Mitova, Angelova, Kachulska; Vasileva, D Georgiva (Pencheva 66), Petrova, Dimova (Karadakova 83); Bandeva (Lukanova 56); S Petkova.
FIXTURES
Republic of Ireland WU19 1-1 Slovenia, Tuesday, September 15
Republic of Ireland WU19 6-0 Bulgaria, Thursday, September 17
Republic of Ireland WU19 v Russia, Sunday, September 20, KO 3.00pm, Gornja Radgona, Slovenia