Hewat stars for Exiles

Back row Declan Danaher crossed in the first half but it was the superb Hewat who made the biggest impression on the scoreboard with five penalties, landing him the man-of-the-match award.

Perpignan's response came from South African Percy Montgomery, who booted nine points with his side failing to capitalise on two dominant spells in the first half.

Irish, featuring in the competition's knockout stages for the first time, will discover their semi-final opponents on Sunday when Toulouse and Cardiff meet.

And their confidence for the last-four showdown at Twickenham will have been sent soaring following their comprehensive victory over one of the Heineken Cup's big guns.

For a match that was simmering with bad blood following two fractious encounters between the rivals in the group stage, there was little evidence of needle.

The only flashpoint arrived in injury time when Perpignan blindside Viliami Vaki was sent off for punching Steffon Armitage amid a large brawl.

Irish focused on using their greater mobility to tip the scales in their favour, while Perpignan's most potent weapon was their pack - but as in the group stages, it was the Exiles who came out on top.

Perpignan, who were frustrated by a try-saving tackle from Paul Hodgson on Adrien Plante, wilted in the second half, with Hewat's superb kicking from hand frequently pinning them back.