Newcastle's new £2m defender Andy O'Brien plundered a controversial first-half winner which revived the Republic of Ireland's hopes of qualifying for the finals of the European Under-21 Championships with a 1-0 win in Cyprus.

But victory left Cyprus fuming over the performance of Romanian referee Dan Tudor, who as well as failing to spot a foul by O'Brien in the build-up to his 18th-minute goal, denied the home side two penalties.

The hosts twice made vociferous appeals when Irish goalkeeper Joe Murphy clattered into forwards who had burst into the area.

But despite a few sticky moments, the Republic thoroughly deserved to follow up their narrow success against Estonia in October, having lost both their opening Group Two qualifiers in Holland and Portugal.

It was a happy return to the GSZ Stadium in Larnaca, where Ireland won the final of the 1998 European Youth Championships on penalties against Germany, with five of the current Under-21 squad on duty.

Murphy's flying save from Elias Charalambous' shot prevented them trailing after only four minutes and also saved the blushes of John O'Shea, who let a long ball bounce beyond him and gave away a free-kick in a dangerous position.

But the Republic youngsters soon settled. Richie Foran smartly intercepted on halfway and quickly set up Sunderland's Michael Reddy, whose pace took him through the Cypriot defence only for Athos Chrisostomou to smother his shot.

Colin Healy's header from a Foran cross was well saved in the tenth minute before the hotly-disputed opening goal came eight minutes later.

A Healy corner was the catalyst for a jumping contest between O'Brien and Chrisostomou and the keeper collapsed in a heap as the ball soared beyond both of them.

Middlesbrough's Jason Gavin, though, neatly headed it back into the goalmouth and O'Brien forced it past the fallen keeper.

The Cyprus players surrounded the referee and protested that O'Brien, yet to make his Newcastle bow after moving from Bradford this week, had fouled the keeper.

The Republic were clearly riding their luck with the decisions but by half-time had established a clear superiority with the pace of Reddy and debut-making Shelbourne striker Foran constantly troubling Cyprus.

James O'Connor's prodigious midfield work-rate was being matched by another debutant, Millwall's Stephen Reid.

Gavin foolishly got himself booked for a rash challenge deep in Cypriot territory early in the second half and will now be banned for the next tie against Portugal in June.

But in the 56th minute it was the Middlesbrough defender who forced another desperate save from Chrisostomou which prevented Ireland going two up.