(Reuters) - The United States hammered St Vincent and the Grenadines 6-0 to move closer to the final CONCACAF World Cup qualifying round on Friday but Canada have a mountain to climb after losing 2-1 in Honduras.

Teenage substitute Christian Pulisic scored a second-half double in the U.S. rout.Three first-half goals had put the result beyond doubt, though the visitors were exposed several times defensively by the plucky team from the small Caribbean island nation of barely 100,000 people.

German-based Bobby Wood opened the scoring in the 28th minute when he curled a shot into the far corner from just outside the box at the Arnos Vale cricket ground in Kingstown. Matt Besler's strike and a Jozy Altidore penalty extended the lead before halftime in breezy conditions.St. Vincent had the ball in the net twice early in the second half, but the goals were ruled offside. Seventeen-year-old Pulisic then showed his class after coming off the bench.

The Borussia Dortmund striker scored his first goal after collecting a pass with a deft touch inside the box and completed the win in stoppage time when he was given too much time just outside the box and placed the ball clinically inside the post.

Sacha Kljestan also scored for the U.S., who are poised to reach the so-called Hexagonal, or final stage, of CONCACAF qualifying.

The U.S. have 10 points from five matches in Group 3, with one game left in the stage against Trinidad and Tobago.

"It's a nice win and the team deserves a compliment," coach Jurgen Klinsmann said after the game, "but we've gotta finish it off Tuesday versus T&T."

The first two teams in each of the three groups qualify for the final round robin Hexagonal, from which the top three will qualify automatically for Russia and the fourth-placed side will go into an intercontinental play off with a team from Asia.

That task looks beyond Canada after their lost 2-1 in Honduras.

James Manjrekar headed Canada into the lead in the 35th minute but Mario Martinez drew the sides level on the stroke of half time.

Romell Quioto, one of the stars of the Honduran Olympic team that reached the semi-finals in Brazil last month, got the home side's winner five minutes into the second period. The defeat leaves Honduras in pole position to qualify from Group 1 behind Mexico, the only team so far to have cemented their place.

Mexico play El Salvador in one of the four games taking place later on Friday.

(Reporting by Andrew Both in Cary, North Carolina and Andrew Downie in Sao Paulo; Editing by Ken Ferris)