George Munsey scored an unbeaten 66 from 53 deliveries to lift Scotland to 160 for five after being sent in to bat in overcast conditions at Hobart.
“It’s a special win for us,” Scotland captain Richie Berrington said. “There’s a lot of hard work that’s gone into this. I’m just extremely proud.”
Disciplined bowling from Scotland resulted in regular wickets and restricted West Indies to 118 in 18.3 overs in reply in the Group B opener.
Left-arm spinner Mark Watt (3-12) opened the bowling and took three wickets, and pace bowler Brad Wheal (2-32) and offspinner Michael Leask (2-15) each took two wickets.
Ireland was playing Zimbabwe later Monday.
The teams placing first and second in each of the preliminary-round groups will advance to the Super 12 round, which starts this weekend with defending champion Australia against New Zealand on Saturday in a rematch of last year’s final.
Scotland qualified for the Super 12 stage last year when the tournament was held in the United Arab Emirates and Oman, including an upset over Bangladesh.
The win over West Indies will rank higher for the Scots, who got away to a flying start with Munsey and Michael Jones (20) putting on a 55-run opening stand, disrupted by a rain delay, before Jason Holder took the first wicket two balls after the powerplay.
Calum MacLeod belted 23 from 14 balls and Chris Greaves finished unbeaten on 16 in other important contributions for the Scotland innings.
Holder (2-14) was the pick of the West Indies bowlers with two wickets in his first two overs, and he also prolonged the run chase in a losing cause with a defiant 38 from 33 balls despite bating with the lower order.
Kyle Mayers scored the first 20 runs for West Indies before he was dismissed in the third over. Evin Lewis (14) and Brandon King (17) took the score to 53-2 in the sixth but their dismissals in back-to-back overs rocked the innings.
“It’s a tough loss for us. Obviously disappointed,” West Indies skipper Nicholas Pooran said. “This loss … makes the next two games must-win for us.
“We have to put this loss behind us and pick ourselves up.” West Indies is the only team to win the T20 world title more than once, and was one of the most dominant teams for a decade in the format. But the retirement of Chris Gayle has left some holes in the the composition of the team.
Pooran’s team needs to rebound quickly with a game against Zimbabwe on Wednesday, when Scotland takes on Ireland.
Scotland hasn’t played a lot of T20 international cricket this year, but Berrington said his lineup was able to quickly convert its form in 50-over cricket into the shorter format.
“Extremely delighted that we managed to do that today,” he said. “I thought our bowlers were exceptional.
The boys put in a great shift … all around a great team performance.”
There was an upset in the tournament opener on Sunday, with Namibia beating former champion and three-time finalist Sri Lanka by 55 runs in Group A.
In a warmup match in Brisbane that didn’t have status as an official T20 international, India took six wickets in the last two overs — including three in a one-over cameo from fast bowler Mohammed Shami — to beat defending T20 world champion Australia by six runs. India took wickets with each of the last four deliveries.