New Zealand 283 for 1 (Conway 152*, Ravindra 123*) beat England 282 for 9 (Root 77, Henry 3-48, Phillips 2-17) by 9 wickets
Ahmedabad: England's defence of their World Cup title began with a nine-wicket hammering at the hands of New Zealand in Ahmedabad.
The rematch of the final four years ago offered none of the tension of that Lord's epic with the Black Caps cantering home in pursuit of 283.
They reached their target with 13.4 overs to spare - Devon Conway and Rachin Ravindra both hitting stunning centuries.
Conway ended 152 not out and Ravindra unbeaten on 123 as the pair combined for a sensational 273-run partnership - the fourth-highest in men's World Cup history - which rendered England's attack toothless.
In contrast, England struggled to 282-9 in a lacklustre batting performance. Joe Root made 77 but a series of soft dismissals checked their progress.
They have to wait until Tuesday for their next match - a meeting with Bangladesh in Dharamshala.
This tournament follows the same format as the last 50-over World Cup, where they lost three times in the 10-team round-robin stage before going on to lift the trophy.
But the way the defeat became increasingly ugly, plus the net run-rate implications, make it a very worrying start.
At halfway their total looked 30 runs below par. Conway and Ravindra's performance made it look more like 100.
Sam Curran had Will Young caught behind down the leg side for a duck to start the second over of the chase but that was as good as it got for England.
A missed chance to run out Conway in the third over the closest they came to another wicket.
Conway latched onto anything short or full - the highlight a glorious straight drive off Mark Wood, whose five overs cost 55.
Fellow left-hander Ravindra, previously with a high score of 61 in international cricket, batted with flamboyance, including one stunning six over Chris Woakes' head in what became a regular flow of boundaries.
Although the crowd increased throughout, the match began in front of less than 10,000 people and swaths of empty seats at the huge, 130,000-seater Narendra Modi Stadium.
England's performance is not the only thing that must improve at this tournament.