The Blackcaps have been decisively beaten in their one-day series-opener against West Indies at Bridgetown.
Losing the toss and sent in to bat, New Zealand were unable to see out their 50 overs, bowled out for 190 runs.
The hosts needed just 39 overs to chase down the modest total, winning by five wickets to take the 1-0 series lead.
New Zealand started their innings steadily and were 41 without loss approaching the end of the first powerplay, but openers Finn Allen (25) and Guptill (24) departed by the 10th over, setting the tone of Blackcaps batters failing to kick on, after battling the slow conditions.
Captain Kane Williamson tried his best to steady the ship, but wickets continued to fall around him, with Devon Conway (4) and Tom Latham (12) departing to leave New Zealand 88/4 after 21 overs.
Williamson looked to have found support in the form of all-rounder Daryl Mitchell, but a double-wicket over from spin-bowler Alzarri Joseph left the Blackcaps reeling.
Mitchell was the first to go for 20, before Williamson was sent on his way just four balls later for a valiant 34 runs.
Michael Bracewell (31) and Mitch Santner (25) tried their best to resurrect the Blackcaps batting, and helped set a modest target of 191 to win for the West Indies.
West Indies opener Shai Hope got the hosts off to a strong start, hitting a quickfire 26, but partner Kyle Mayers (6) fell cheaply off the bowling of Tim Southee.
Hope departed just three overs later for 26 runs, after Trent Boult found the edge to wicketkeeper Latham, as it looked like the home team would also struggle with the bat.
But Hope's dismissal would see the arrival of Shamarh Brooks, who struck a masterful 79 runs, including 10 boundaries.
Brooks was well supported by West Indies captain Nicholas Pooran (28), before a couple of late wickets only delayed the inevitable.
Southee and Boult picked up two wickets apiece, but Jermain Blackwood and Jason Holder made sure the West Indies got over the line with plenty of overs to spare.
New Zealand 190 (Williamson 34, Bracewell 31; Hosein 3/28) West Indies 193/5 (Brooks 79, Pooran 28; Southee 2/38)
West Indies win by five wickets
