Fly-half Patchell was bulldozed by flanker CJ Stander in the build-up to the game's first try, as boss Joe Schmidt toasted his final match at the Aviva Stadium by steering Ireland to the top of World Rugby's rankings.
Wales confirmed that Patchell failed a Head Injury Assessment (HIA) and had suffered a concussion, the number 10 lasting little more than 20 minutes.
Now head coach Warren Gatland will face a nervous wait to see if the 26-year-old can recover in time for the World Cup, with Wales kick-starting their Pool D campaign against Georgia on September 23.
— Irish Rugby (@IrishRugby) September 7, 2019
Head coach Schmidt and captain Rory Best will relinquish their roles after the World Cup, and both claimed the Aviva Stadium sign-off they so craved.
Scarlets playmaker Patchell this week dubbed concussion the "invisible injury", when running the rule over a torrid year including two head injuries and a torn hamstring.
The talented outside-half will be desperately hoping for some good news now though, with his World Cup adventure in the balance. Saturday's Dublin clash was his first Wales start in 15 months, and his rotten injury luck struck again.
Wales fly out to Japan on Wednesday and Cardiff Blues' Jarrod Evans would be a straight replacement for Patchell should boss Gatland need to make an early injury switch into his 31-man squad.
Ireland wobbled at the lineout again from the off, Joe Schmidt's side still getting to grips with the absence of set-piece banker Devin Toner.
Brian O'Driscoll this week insisted omitting Toner from Ireland's World Cup squad "beggars belief", and early on here the lineout jitters certainly backed that stance.
Captain Rory Best and locks James Ryan and Jean Kleyn warmed to their set-piece task however, with one penalty lineout laying the platform for the game's first score.
Bundee Aki and Stander powered through Wales' midfield, with the latter clattering Patchell and ending the fly-half's afternoon prematurely. That quick ball allowed Kearney to ghost past Jonathan Davies and across the whitewash, with a sharp-looking Johnny Sexton posting a smart conversion.
Biggar snatched an interception pass off Sexton to race towards the line, only for Henshaw to haul back the replacement fly-half and deny him a score.
Ireland built their fluency after the break though, Conor Murray and Sexton running the show in what will prove a huge relief to boss Schmidt.
Tighthead prop Furlong powered home to wrestle the lead back into Irish hands and then lock Ryan busted in too.
Jack Carty replaced Sexton just past the hour, with Ireland's premier playmaker withdrawn safe and sound – to be bubble-wrapped en route to Japan such is his importance to Schmidt's side.
Scrum-half Murray negotiated the encounter unscathed too, which will relieve the Irish public just as much as boss Schmidt.
Adam Beard was sin-binned at the death for Wales, paying the price for the visitors' repeated infringement, before Ireland closed out their spirited win.