The victory went some way to helping the nation rebound from a disappointing 3-1 loss to Mexico on Saturday.
Tuesday's win came in the final match of a U.S. hosted international gathering, serving as a tune-up for June's 2011 CONCACAF Gold Cup.
Oscar Cardoza netted Paraguay's goal in the 17th minute off a corner, while goalkeeper Justo Villar preserved the win with some great saves in the second half.
The U.S. had more than their share of opportunities and out-shot Paraguay 13-5 but could not finish numerous second-half chances.
One consolation for the hosts was another promising performance from 18-year-old Juan Agudelo, making his first start with the national team.
The U.S. were coming off an encouraging 1-1 draw against Lionel Messi and Argentina in their first match of these friendlies.
The Americans reached the 2009 CONCACAF Gold Cup final en route to reaching the round of 16 in last year's World Cup.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.