Aston Villa defender Clark thumped home a 35th-minute shot to give Ireland the lead against the run of play, before Norwich midfielder Hoolahan, the former Livingston player, introduced as a second-half replacement for Shane Long, cemented victory 14 minutes from time with an accomplished finish.
The scoreline perhaps flattered Giovanni Trapattoni’s men, decidedly second-best before the break. However, goalkeeper David Forde responded to the challenge of being brought into the starting line-up with a series of important saves to keep them in it. And, as the game wore on, the hosts grew in confidence and finished strongly to remind their fans of the heady days before a disastrous Euro 2012 campaign.
Michael O’Neill is still looking for his first win as Northern Ireland manager after they were held to a 0-0 draw by Malta at Ta’qali National Stadium. It is the fifth draw from eight games for O’Neill, while Northern Ireland are without a win since beating the Faroe Islands in August 2011.
Gareth McAuley did have the ball in the net in the 18th minute but it was ruled out for pushing and the visitors were grateful to St Johnstone goalkeeper Alan Mannus for two very good saves to deny Michael Mifsud.
Aberdeen’s Niall McGinn threatened on a couple of occasions, while Inverness striker Billy McKay won his first cap as a second-half substitute. Celtic’s Pat McCourt and Aberdeen’s Josh Magennis were introduced late on but there was no way through the Malta defence.
Two early goals helped the Czech Republic heap more problems on struggling Turkey with a 2-0 win at the Ataturk Olympic Stadium. Ladislav Krejci opened the scoring in the fourth minute and David Lafata added a second in the 28th minute.
Spain warmed up for their potentially crucial World Cup qualifying double header against Finland and France with a 3-1 win over Copa America champions Uruguay in Doha.
Cesc Fabregas’ early goal was wiped out by a Cristian Rodriguez equaliser but a second-half brace from Pedro Rodriguez earned Spain the victory in a match which saw defender Carles Puyol make his 100th appearance for the reigning world and European champions.
Bosnia-Herzegovina were 3-0 friendly winners over Slovenia.