Wales star Gareth Bale had, unsurprisingly, been highlighted as the dangerman before the last-16 tie at the Parc des Princes but was largely stifled in a tense all-British affair.
However, the Real Madrid man showed his quality with a teasing left-wing cross that the unfortunate McAuley diverted into his own net when sliding to make a clearance with 15 minutes remaining.
In truth the expected blood-and-thunder derby-type contest never materialised, but Wales will feel they did enough to justify their place in the last eight with Sam Vokes missing a great second-half opportunity and Bale testing Michael McGovern - so impressive in the 1-0 loss to Germany - with a free-kick.
Northern Ireland were hard working off the ball and tactically shrewd, but a lack of penetration in the final third ultimately meant Michael O'Neill's men and the boisterous Northern Irish fans were consigned to the plane home.
There was little to split the teams in a tetchy opening phase with Northern Ireland doing well to close down Wales' full-backs and limit the space for Bale.
And it was Northern Ireland who mustered the first chance of note in the 10th minute when a swift counter-attack led to Stuart Dallas testing Wayne Hennessey with a left-footed drive from the edge of the box.
Wales slowly gained a foothold in the game and Aaron Ramsey did poke home from Vokes' powerful headed knockdown only to be rightly flagged for offside.
Hennessey was then alert to tip Jamie Ward's long-distance drive over the crossbar, but by-and-large the half proved a war of attrition with few chances created and it was goalless by the break.
The tight nature of the match continued after the restart, but Wales had a great opportunity in the 53rd minute when Aaron Ramsey's deep cross was wastefully headed wide of the right post by the unmarked Vokes.
Wales began to up the tempo and Bale forced McGovern into his first proper save with a well-struck dipping free-kick from 25 yards, before the Real Madrid forward saw claims for handball against Jonny Evans in the area fall on death ears.
Bale, who had scored three in three in the group stages, did make a telling contribution in the 75th-minute, though. He found space wide left and McAuley poked the ball past McGovern when trying to prevent Robson-Kanu tapping in.
There was a moment of worry for Wales when namesakes Ashley and Jonny Williams collided heavily - the former continuing despite apparent damage to his left arm.
That led to four minutes of additional time, but Northern Ireland were unable to muster a reply and it was the red shirts in the stadium that were left to celebrate a quarter-final berth.