Jason Roy and captain Joe Root both smashed centuries as the tourists easily reached their target of 361 with eight balls to spare in Barbados.
It was their highest ever run-chase in the format.
Chris Gayle's innings of 139 off 129 balls went in vain as the Windies' poor form in ODI cricket continued.
The second encounter of the five-match series will be played on Friday.
Ten-man Newcastle beat Man United; Arsenal go 7 points clear
William Osula came off the bench to score a late winner as a 10-man Newcastle United beat high-flying Manchester United 2-1 in the Premier League on Wednesday to end Michael Carrick's unbeaten run as interim manager.
New Zealand crush South Africa to reach T20 World Cup final
Finn Allen plundered the fastest century in Twenty20 World Cup history to lead New Zealand into the final with a nine-wicket demolition of South Africa at the Eden Gardens on Wednesday.
Dave Rennie becomes first Pacific Islander to lead All Blacks
Dave Rennie was named as replacement for Scott Robertson as coach of the All Blacks on Wednesday and charged with taking New Zealand to a fourth World Cup triumph in Australia next year.
FIFA offering $12 tickets to World Cup Play-Off Tournament
Tickets for this month's World Cup Play-Off Tournament matches in Mexico, which will determine two of the final six vacant spots in this summer's historic 48-team tournament, went on sale Tuesday.
Resurgent Wolves stun Liverpool, Everton enjoy home comfort
Resurgent bottom club Wolverhampton Wanderers have stunned Liverpool with a last-gasp 2-1 win at a rocking Molineux on Tuesday to offer a glimpse of a miraculous escape from relegation while putting a big dent in the top-five hopes of Arne Slot's side.
