The United States lead Colombia 1-0 at the interval following a Megan Rapinoe strike after 33 minutes.
It was the United States who started the better and they might have taken the lead after just six minutes, but Lauren Cheney fired wide from close range.
The US continued to dominate in the opening stages, and Abby Wambach also fired wide from inside the box in a lively opening from the favourites.
Chances continued to fall their way as the half-hour mark approached, and Alex Morgan and Rapinoe were both guilty of missing openings.
Colombia's clearest chance of the half fell to Carmen Rodallega, but she fired a stinging effort over the crossbar.
The US did take the lead, however, after 33 minutes when Rapinoe finished a sweeping move with ease.
It remained that way until the break, but it was so nearly two on the stroke of the interval when Rapinoe met a low cross - but the danger was cleared.
Matt Law
