Set an uncomplicated target of 83, the Windwards needed just 74 balls to complete victory at the Beausejour Cricket Ground, about 45 minutes after lunch on the penultimate day of their seventh round encounter.
Seasoned opener Devon Smith continued his rich vein of form, stroking an unbeaten 39 off 33 balls with four fours and a six. He added 42 off 26 balls for the first wicket with Johnson Charles whose 27 required 18 deliveries and included three fours and a six.
Seamer Gavin Tonge removed Charles in the fourth over before lunch, as the Windwards went to the break on 58 for one.
The hosts wasted little time on resumption in speeding to their target, with Smith finishing the game in style by clearing the ropes with off-spinner Rahkeem Cornwall.
Earlier, the Leewards were dismissed for 170 in their second innings, after resuming the day on 137 for six.
Orlando Peters failed to add to his overnight 27 and it was left up to Jeremiah Louis, with 25 off 71 balls in 81 minutes at the crease overall, to eke out precious runs at the end for the visitors.
Seamer Mervin Matthew finished with five for 32 while left-arm pacer Delorn Johnson picked up three for 48.
With the victory, the Windwards moved to 80 points to stay in touch with leaders Guyana Jaguars and second placed Barbados Pride.
The Leewards remain rooted to the bottom of the standings on 17 points.