Scotland made 160-5, with opener George Munsey striking an unbeaten 66 from 53 balls.

Ireland start their campaign against Zimbabwe in the other Group B game.

"It is a special win for us," said Scotland captain Richard Berrington, whose side beat Bangladesh in last year's World Cup. "A lot of hard work has gone into getting us to this point in the last 12 months.

"I'm extremely proud of the boys for going out there tonight and showing off our skills."

The result means West Indies, who are ranked seventh in the world, will likely need to win both of their remaining games to progress.

They face Zimbabwe on Wednesday (09:00 BST), while Scotland face Ireland (05:00) knowing a victory will likely see them qualify.

The top two sides from each group will qualify for the Super 12s, which start on 22 October. The winner of Group A and runner-up from Group B will face England.

Scotland get it right, while Windies disappoint

Scotland raced to 52-0 after 5.3 overs - a stark improvement on their opening stands in last year's tournament, where their highest score was 33 - before a 45-minute rain delay halted their progress.

Windies started poorly with the ball, offering too much width, but were much improved after the break, banging the ball effectively into the pitch.

It slowed the scoring rate significantly and also brought the wickets of Matthew Cross and Richard Berrington, as both flat-batted to mid-on and mid-wicket respectively.

Munsey lacked fluency after the delay but stuck at it, and reaped his rewards as he clubbed three boundaries from the final over, having hit his previous one in the fourth over.

There were also powerful cameos from Callum MacLeod (23 off 14) and Chris Greaves (16 off 11) as Scotland dragged themselves up to a defendable, but potentially not match-winning, total.

As was the case last year, Windies were woeful with the bat. It felt like it was shot or block with minimal ability to rotate the strike.

They particularly struggled against the left-arm spin of Mark Watt, who regularly bowled from 24 yards instead of 22, and off-spin of Michael Leask, with the pair taking 3-12 and 2-15 respectively, while bowling 27 dot balls.

Pace bowler Brad Wheal, who was part of the Hampshire side that won the T20 Blast this summer, also bowled well, claiming 2-32.

Scotland were also faultless in the field, including a superb catch from Leask, running in from the mid-wicket boundary to dismiss Shamarh Brooks.

Berrington added: "We knew it was a competitive score and I thought the bowlers were exceptional. The spinners have done it for us for a long time now at key moments. They put in a great shift - it was an all-round great team performance."

West Indies captain Nicholas Pooran believes 161 was a score his side should have chased, saying: "It is a tough loss for us, we're disappointed.

"We need to do the hard work now and win two games, it is all about accountability now."

Scotland have only played two T20s since last year's World Cup in the United Arab Emirates, which makes their victory, and the consistency of their skills, even more remarkable.

Batter Callum MacLeod said: "There wasn't a huge amount of surprise that Namibia won yesterday and we won today - that is where we're at with our cricket. We've all been crying out for more opportunities and it would be great to see where some of the associate nations could get to if we were invited into the game sometimes.

"Wins in global events are significant, they have more on them. The win over Bangladesh last year was a special moment but today was probably a better win - we probably played the better cricket from start to finish and deserved to win."