Riki Flutey and Phil Murphy scored a try apiece for the Exiles while fly-half Barry Everitt claimed 13 points with the boot as Newcastle slumped to their fifth Premiership defeat of the season.
Jonny Wilkinson kicked 15 points and Matt Burke scored a try for Newcastle to claim a bonus point, but it still keeps them second from bottom on the Premiership table.
Wilkinson and Everitt exchanged penalties in the opening 15 minutes before Burke rounded off a solid piece of work from Mathew Tait for their try.
However the Falcons pack could not assert themselves on to the game and Irish edged ahead through two Everitt penalties.
Just before the break Everitt set up their first try as he surged into space before linking well with Mike Catt who fed fullback Flutey to score under the posts.
Everitt’s conversion made it 16-8 at half-time, and the visitors claimed their second soon after the break after a superb pack effort. No.8 Murphy was the man at the bottom of the maul and
Everitt increased the lead to 23-8 with the conversion.
Wilkinson narrowed the gap to nine points with two penalties as Newcastle began to claw their way back into the game.
Colin Charvis, back from international duty with Wales, was all over the park hassling the Irish backs and his speed to the breakdown resulted in another Wilkinson penalty.
With time running out, Wilkinson narrowed the gap to three points, but despite a valiant effort the Irish defence held firm.