The 2011 champions destroyed Windies??? top and middle order in Perth, reducing their opponents to 35-4 and 85-7 before Jason Holder (57 off 64 balls) helped the Caribbean outfit scramble their way to 182 all out.
India endured plenty of batting jitters of their own, but captain MS Dhoni (45no) steered his side over the line and to a fourth straight World Cup win, following earlier successes over Pakistan, South Africa and UAE.
West Indies, who opted to bat, made a dawdling start to their innings and were two down with just 15 on the board in the eighth over, Mohammed Shami (3-35) snaffling Dwayne Smith (6) caught behind and Chris Gayle???s dallying leading to Marlon Samuels (2) being run out by Virat Kohli.
Gayle???s day got worse when we was pouched at deep square leg after pulling Shami, while Denesh Ramdin (0) departed for a golden duck one ball later, cleaned up by the rapid Umesh Yadav (2-42).
West Indies??? batting effort was in tatters when Lendl Simmons (9), Jonathan Carter (21) and Andre Russell (8) were dismissed, but skipper Holder, with the help of former captain Darren Sammy (22 from 55 balls), then launched a counter-attack.
The 23-year-old clubbed four fours and three sixes as he attained his highest ODI score ??? bettering the 56 he notched in West Indies??? walloping by South Africa last time out ??? and gave his country at least something to defend, four dropped catches from India also aiding their cause.
Holder put on 39 with Sammy and then 51 with Jerome Taylor (11) in seven overs, before plinking to Kohli at long-on to leave last man Kemar Roach (0) stranded with 44.2 overs having been bowled.
West Indies needed early inroads and Taylor got two of them, the Jamaican forcing Shikhar Dhawan (9) to nick off to Sammy in the slip cordon and Rohit Sharma (7) to feather a late out-swinger into Ramdin???s gloves.
India were 20-2 at that stage but Kohli???s enjoyable knock ??? the Delhi native making 33 from 36 deliveries with five fours ??? allowed Dhoni???s charges to steady themselves.
The Asian outfit had another wobble, though, when Kohli and Rahane exited in quick succession ??? the latter given out caught behind down the leg side despite his review failing to conclusively prove the ball had hit the bat ??? and Suresh Raina (22) flashed medium-pacer Smith through to Ramdin.
Ravindra Jadeja (13) frayed Indian fans??? nerves even further when he hooked to a juggling Samuels with the score on 134, but Dhoni and Ravichandran Ashwin (16) held firm with a partnership of??51 to seal the win with 65 balls to spare.
West Indies have now won two and lost three of their Pool B encounters, though they can still qualify for the knockout stages if they beat UAE in Napier on March 15 and other results go their way.