Having lost their opening Super 8s match to England, the Windies bounced back in style in Barbados on Friday.
Shai Hope's unbeaten 82, which came from 39 balls and included eight sixes, three of which came on the bounce, saw West Indies surpass the target of just 129 within 11 overs.
Hope was recalled to the team after an injury to Brandon King, but will be a tough drop for Rovman Powell now.
The USA had made a promising start, but slipped from 51-1 to 65-4 in the space of three overs, with Andre Russell the pick of the Windies' bowlers (3-31). Andre Gous (29) and Nitish Kumar (20) were the best scores on the board, as they were skittled out for 128.
Hope, Johnson Charles (15) and Nicholas Pooran (27 not out) then wasted little time in securing a margin of victory that sends West Indies above England in Group 2, while their net run rate is also superior to South Africa's.
The Proteas are West Indies' final opponents, while defending champions England face the USA in their last Super 8s match.
Data Debrief: Windies in fine fettle
West Indies have now won nine of their 11 T20Is in 2024, after winning eight games in each of 2022 and 2023.
Their tally of victories this year matches 2021 as their best effort in a single calendar year.
They have also won five of their last seven T20Is at Kensington Oval, and their last three in a row.
Stoute scored 86 and Ambris 70 and their third-wicket partnership of 119 laid the foundation for the Windwards’ 284 all out off 49.2 overs.
They came together after Kimani Melius and Desron Maloney were already back in the pavilion midway the eighth over with 40 runs on the board.
When Ambris departed for 70 that included eight fours and a six, Stoute and Emmanuel Stewart put on 68 for the fourth wicket when Stoute got out in the 42nd over. Stewart was out five balls later but Roland Cato (11) and Rayon John (15) helped push the final score to 284.
Bowling for the Leewards Quinton Boatswain took 4 -45 from his 10 overs while Sheeno Berridge 3-65 and Hayden Walsh 3-79 provided support.
Chasing 285, the Leewards were dismissed for 253 in 49.3 overs despite Kumar’s 112 from 106 balls that included nine fours and two sixes.
He put on 43 for the third wicket with Ross Powell, who made 46 and 79 for the fifth wicket with Montcin Hodge who made 28 but there were never enough partnerships to take Leewards to the target as Preston McSween, Larry Edward, Ray Jordan and Kerron Cottoy each took two wickets to stymie the run chase.
On Monday, the Guyana Jaguars will face the Barbados Pride at the same venue.
In their T20 World Cup debut, the US have two wins from two and top Group A after beating Canada in their opener before following it up with another statement victory.
The US opted to let Pakistan bat first, limiting them to 159-7, and chased down the target exceptionally well, with Nitish Kumar hitting a four on the final ball to force a super over.
Pakistan still had no answers, falling to a five-run defeat in their opening game at the tournament.
Patel did not play in their opening game against Canada but came in to get 50 off 38 balls, including two fours and two boundaries, but quickly shifted the focus to the whole team.
"Playing in the World Cup, you don't get a chance to do it every year," he said. "We knew we had to be fully committed [to] every single ball against Pakistan. It was a complete effort from the team.
"It's a big achievement - beating Pakistan while playing for the first time. Complete performance. We used the conditions well. Kept them to 160, which was chaseable. Happy with my contribution, happier to have won.
"Plan was to have a big partnership among top three and then to take it deep. [Andries] Gous played cricketing shots and took pressure away. As a player and captain, you want to show off your talent on the big occasion. Wanted to score in a winning cause."
Pakistan struggled to get going, with captain Babar Azam finishing on 44 after a slow start to the game saw them struggle to build any momentum.
Despite eventually finishing the first innings strongly, Pakistan struggled to limit the US' chase, with errors creeping into their game to keep the tournament co-hosts in with a chance.
Azam highlighted their slow starts to both innings as their shortcomings in the loss.
"First six overs while batting, we couldn't capitalise. We took momentum but back-to-back wickets hurt us," he said.
"We were not up to the mark in the first six [while bowling]. Didn't take wickets, spinners didn't either. We came back in the end but couldn't finish well. Hope to do well in the future.
"[Result makes it] very hard. All credit to USA who did well in all three departments. That's why they won. There was moisture in the pitch. It was two-paced. As professionals, we had to assess conditions better."
