The Republic of Ireland extended their uninterrupted stay in the second tier of the UEFA Nations League (UNL) to a fifth successive season when they defeated Bulgaria 4-2 over two legs to retain their League B status.

Leading 1-0 on aggregate, the Republic of Ireland had only one job to do on their home turf. Not content to rest on their laurels, however, they set about extending their advantage within the first five minutes.

It almost paid off when Jake O'Brien's header from Robbie Brady's corner was cleared off the line by Plamen Iliev.

Then came the kind of sweeping attack that new Ireland boss Heimir Hallgrímsson has been praised for, and Brady was involved again, this time cutting back for Troy Parrott, who fired against the post.

However, despite the Boys in Green's early efforts, it was Bulgaria who took the lead after that initial flurry.

It was certainly not a pretty one, as Georgi Milanov's volley from the edge of the area was kindly deflected into the path of Valentin Antov, who slotted into the corner to silence the home fans.

Ireland were quick to respond and the first half ended with a sense of déjà vu as another O'Brien header from a Brady corner was saved, this time by goalscorer Antov.

With the scores level at the break, Ireland knew they had to find something special to regain their advantage and they almost did so within 10 minutes of the restart when Evan Ferguson broke free but his effort was tipped around the post by Iliev.

But that was only a temporary reprieve for Bulgaria, who were punished by Ferguson moments later when the West Ham loanee played a neat one-two with Finn Azaz before firing high into the roof of the net.

Hallgrímsson changed tactics with 15 minutes remaining, bringing on centre-back Jimmy Dunne for his international debut and switching to a back five in an attempt to shore up his defence.

He didn't have to worry too much about late pressure, though, as his side wrapped things up in the closing stages when Adam Idah converted Mark Sykes' delivery to book Ireland's League B ticket to the next edition of the UNL.

Bulgaria, meanwhile, are consigned to League C for the third year in a row.