This isn't some Richie McJesus team out to delete your souls for having the temerity to not lose by 20 points the last time you played them. It's a motley collection of over-the-hill players, out-of-position players, and selection contradictions coached by a distinctly average Super Rugby level coach. The Wallabies get spanked in similar situations because they try and beat the NZ national rugby team at NZ rugby; probably also garnished with some mental blocks. Unless something goes seriously badly wrong, then the Irish shouldn't have that problem.
There's only two ways I can see the AB's winning. First is the return of Laulala and Whitelock (and S.Barrett also playing) enabling the AB's to actively take complete control of the set piece, and Whitelock is allowed to maul every lineout for all its worth. Would turn the match into a cavalcade of scrum penalties leading to lineouts, leading to mauls, leading to further penalties, leading to points or more lineouts, and on it goes. Basically the Crusaders post-season strategy. But with a weaker kicking game. If that isn't happening, then they're passively stuck relying on Ireland panicking and/or loosing Sexton early enough (leading to the panic). At that point basketball rugby can pile on the points, as happened at Eden Park.
tldr: Ireland favourites unless Sexton literally dies or Whitelock carries the day.