The Girls in Green made a barely believable start, nearly taking the lead through Kyra Carusa before McCabe opened the scoring from the resulting set-piece, catching Kailen Sheridan off guard as she swung her corner over the goalkeeper and into the back of the net.
That rattled the Canucks, who were firm favourites for the clash but did not create a chance of note until after the half-hour mark, when Vanessa Giles stabbed over from close range.
At the other end, Carusa, whose pace and power caused all kinds of problems, came close to doubling the lead when her angled shot was palmed away to safety.
That miss proved costly when Canada levelled deep into first-half stoppage time in cruel circumstances, as Ireland’s Megan Connolly inadvertently diverted a cross into her own net.
That awakened Bev Priestman’s side, who played with much more energy after the break and would have taken the lead within minutes of the restart had Courtney Brosnan not made a full-stretch save from Jordyn Huitema’s long-range drive.
Minutes later though, that goal finally came thanks to Adriana Leon prodding home from near the penalty spot to complete the turnaround.
Christine Sinclair, introduced at half-time, was twice thwarted in her attempt to score at a record sixth WWC as her shots were saved by Brosnan, who also caught Huitema’s towering header.
Searching for a third goal left Canada open to a sucker punch at the other end, and one was nearly provided by McCabe when her mazy run ended in a shot that was deflected narrowly wide.
There was to be no Ireland comeback though, meaning their dream of qualifying for the knockout stages is over, whereas Canada know a point from their final game against Australia is likely to be enough to progress to the last 16.
Flashscore Player of the Match: Jordyn Huitema (Canada)
