Midfielder Angela Hucles scored the winning goal two minutes into second half stoppage time on an innocent-looking through ball that skidded by the right leg of goalkeeper Erin McLeod and under her arms before rolling into the net.
With the win, U.S. Soccer took home a $200,000 first place prize while Canada earned $50,000 for second. Hucles won the Golden Ball as the Most Valuable Player in the tournament. Canada's Christine Sinclair won the Silver Ball and U.S. forward Abby Wambach won the Bronze Ball.
"It was a battle, but you want to finish in the final, finish with a goal and finish first and we did that," Sundhage said. "It was great for us to come up with a win that way. The energy we got from this game, we will bring to Beijing."
Sundhage will announce the 18 players she will take to the Olympics -- and three alternates -- on Monday.
The USA previously downed China in January for the championship of the Four Nations Tournament, defeated Denmark for the Algarve Cup title in March and beat Canada in penalty kicks in the final of Concacaf Women's Olympic Qualifying in April.
The win moves the USA to 17-0-1 in 2008 with four friendly matches remaining before the 2008 Olympics. The leaves for Europe on June 27 to play matches against Norway (on July 2 in Fredrikstad) and Sweden (on July 5 in Skelleftea). It concludes its pre-Olympics schedule with games against Brazil in mid-July.
June 21 in Suwon
USA 1 Canada 0. Goal: Hucles 92+.
USA -- Solo, Mitts, Buehler, Rampone, Chalupny, Boxx, Lloyd (Hucles, 46), Wagner (O'Reilly, 75), Tarpley (Cheney, 46), Kai, Wambach.
Canada -- McLeod, Zurrer, Rustad, Hermus, Chapman, Matheson, Wilkinson, Allen (Timko, 30), Sinclair, Tancredi, Lang.
Referee: Alexandra Ihringova (England).