'That was as fine a round of golf as you will see at the amateur level,' said U.S. captain O. Gordon Brewer, Jr. 'He picked the team up on his shoulders.'
Trahan collected five birdies and an eagle on his round to go along with one bogey. Ricky Barnes, the 2002 U.S. Amateur champion, added a 2-over 74 for a team score of 4-under 140 on the final day. The U.S. finished at 8-under-par 568 for the tournament, three strokes clear of France.
'We are disappointed but we are very proud for our country and our game in this championship and under this pressure,' said Raphael Pellicioli of France.
France took a three-shot lead into the final round, but could not hold off the Americans. The French second-place finish is their highest in 23 appearances in the tournament.
Australia and the Philippines finished tied for third at 2-under-par 574, while Austria and New Zealand were tied for fifth at 1-under-par 575.
The World Amateur Team Championships are conducted by the World Amateur Golf Council. The Championships are a biennial international competition.