Haiti, which defeated the Dominican Republic in the evening's first match, is in first place with four points.
In an even first half, both teams played a waiting game as a premium was placed on denying, rather than producing, opportunities. The action was principally wedged in the midfield and the forwards were left mostly anonymous.
Hughton Hector had the best chance for Trinidad in the 38th minute, but his shot from just inside the 18-yard box was parried by Molvin James for a corner. The Antiguan goalkeeper flashed his talents once again two minutes later, thwarting Atullah Guerra from close range.
Antigua's Kimoi Alexander created a semi-chance just before the break that failed to bother Soca Warriors goalkeeper Jan Michael Williams.
Quinton Griffith gave the home supporters something for which to cheer, conjuring a moment of magic in the 51st minute to give the Benna Boys a 1-0 lead. The 20-year-old defender collected a rebound of his own free kick and lashed it past Williams from 20-yards out.
Randolph Burton nearly doubled the advantage a few moments later, hitting the crossbar after being on the receiving end of unselfish service by Tamorley Thomas.
Kevin Molino tried to bring the visitors on level terms in the 65th minute with a low volley that James handled easily. Devon Jorsling hit the crossbar just a few minutes after.
Antigua secured the needed insurance goal in the 73rd minute and it had the dependable Peter Byers to thank. The 28-year-old forward got into the box and after a hesitation dribble, slipped a shot past Williams for his second tally in two Caribbean Cup games.
Group A, which was expected to be tightly contested, concludes play with a Tuesday doubleheader. In the opener, Trinidad & Tobago will need to beat the Dominican Republic to have any hope of progressing. Immediately afterwards, Antigua will take on Haiti.
The top two teams will advance to the semifinals and book tickets to the 2013 CONCACAF Gold Cup.