Otto Pfister's side needed to win the match after a surprise 2-1 defeat to Bermuda in Hamilton on Friday meant the Soca Warriors were already three points behind Group B rivals Guyana in their bid to move into the next stage of qualification.
And they delivered in style as Peltier hit the first three at Hasely Crawford Stadium in Port of Spain before Hughton Hector added a fourth.
Also in Group B, Bermuda and Guyana drew 1-1 to further boost Pfister's side as Ricky Shakes levelled for the visitors following John Barry Nusum's opener for the hosts.
While the draw meant Puerto Rico cannot move into the next round from Group D, they were happy with a case of 'mission accomplished' as Canada took the initiative without making a breakthrough.
St Kitts and Nevis drew 1-1 at home to St Lucia.
In Group C, Panama smashed Nicaragua 5-1 as Blas Perez hit a hat-trick and Luis Tejada scored two for the home side.