Fighting half-centuries from Avier Christian (51) and Jeremiah Louis (53) added some respectability to the Leewards second innings, as they plummeted from 18 without loss to 28 for three.
Fabian Allen rocked the Leewards’ top order, snatching four for 47, and Christopher Powell took three for 40, preventing the Leeward Islands batsmen from settling down.
Openers Odaine McCatty and Leroy Lug knocked off a Jamaican victory target of 24 runs in less than five overs.
Earlier, Jamaica had declared their first innings at 304 for nine.
Over at Conaree, Windwards squandered an opportunity to come from behind and beat Guyana, who romped to a 140-run win.
Guyana, resuming the final day on 42 for three, soon plunged to 70 for five.
However, Tagenarine Chanderpaul hit an unbeaten 66 from 136 balls, which contained eight fours to provide the stability Guyana required.
Larry Edward grabbed five for 37 to lead the Windwards’ fightback, which left them needing 237 runs for victory.
However, the batsmen did not have the fighting spirit and collapsed to 96 all out.
Keone George top scored with 30, while the second highest score was from Taryck Gabriel, who made 19.
Gudakesh Motie-Kanhai (4-20) and Vishoa Narayan (3-9) led the Guyanese to victory.
Earlier, Guyana had declared at 334 for nine in their first innings.
And, at Warner Park, Barbados escaped with a draw in their third-round clash against Trinidad and Tobago.
Chasing 194 to win, Barbados seemed to be playing for a draw at the tea break.
They were crawling along at 80 for three after 37 overs.
But some quick wickets after the tea interval gave the Trinidadians a glimmer of hope as Barbados were wobbling on 120 for seven with seven overs remaining.
However, an unbroken eighth-wicket partnership between Jofra Archer (13) and Jerome Jones (7) ensured Barbados a draw, as they closed on 134 for 7.
Jamaica’s victory has virtually moved them out of sight at the top of the table on 31.5 points, while Barbados and Trinidad and Tobago have 22.9 and 22.1 points, respectively.
Leewards are on 18.7 points, Guyana, 12.5, and Windwards, 7.7 points.