Keith Earls scored his 35th international try inside six minutes as Andy Farrell’s side flew out of the blocks at a sold-out Eden Park but things swiftly unravelled on a punishing evening.
Influential fly-half Sexton was forced off in the aftermath of Reece’s breakaway try and later failed a head injury assessment to compound a miserable outing.
Ireland, who made the scoreline more respectable thanks to second-half scores from Garry Ringrose and New Zealand-born Bundee Aki, paid a heavy price for repeated defensive lapses and face an uphill task to salvage the series.
Victory for the physical hosts avenged November’s 29-20 defeat in Dublin and maintained their impressive 28-year unbeaten run in a stadium which has become a fortress.
Ireland head coach Farrell also saw Joey Carbery and Josh Van Der Flier each denied certain tries by superb interventions from All Blacks centre Rieko Ioane.
The Englishman must quickly galvanise his dispirited squad ahead of next week’s meeting in Dunedin, for which he is likely to be without Sexton.