's second-period shorthanded goal snapped a 1-1 tie and sparked the U.S. to a 3-1 victory against the host Czech Republic on Friday at the 2011 Five Nations Tournament.
The U.S. improved to 3-0, with its final game coming Sunday against Finland.
"This was a tough win against a hard-working Czech team," U.S. coach Ron Rolston told USA Hockey's website. "We found a way to win, and I'm extremely proud of our guys."
Pietila, who plays for the U.S. National Team Development Program, is No. 112 on NHL Central Scouting's mid-term ranking of North American skaters for the 2011 Entry Draft.
passed to Pietila, who broke in alone, deked to his backhand and deposited the puck behind the Czech goalie Patrik Bartosak.
and Nicolas Kerdiles also scored for the U.S., and goalie John Gibson
, Central Scouting's top-rated netminder, picked up the win.
For more on Gibson's season, take a look at this profile Mike Morreale wrote on him earlier this season
assisted on Boucher's goal, giving him a team-leading 8 points.
In three games at the tournament, the U.S. has outscored it's opponents 19-7.