Canada lead the United States 1-0 at the interval of their Olympic semi-final clash at Old Trafford.
It was the United States who started the better, and they might have led inside five minutes when Megan Rapinoe struck from inside the box, but it drifted just wide.
The US continued to create the better chances in the early stages, with Alex Morgan and Abby Wambach causing the Canadians problems with their attacking running.
Canada did grow into the half, however, with Christine Sinclair and Melissa Tancredi looking to link inside the opposition half.
Carli Lloyd was next to come close for the US after 16 minutes, but her strike was pushed away by Erin McLeod.
Canada took the lead with 23 minutes on the clock, however, when Sinclair danced into the box before finding the bottom corner.
Morgan continued to go close for the US, and the striker headed just wide after 31 minutes. The US continued to push in the latter stages of the half, but they could not break through.
