The United States has claimed one of the biggest wins in its Olympic women's field hockey history, defeating world No. 2 Argentina 2-1 in its opening match.

Argentina's Agustina Albertarrio appeared to break a scoreless tie two minutes into the third period on Saturday, but the goal was nullified. Three minutes later, USA's Katie Reinprecht slipped one under the goalkeeper to give the Americans a 1-0 lead.

Michelle Kasold scored for the USA on a penalty corner with 10:26 to play. Delfina Merino scored for Argentina with 3:27 remaining, but he Americans held on.

The Americans haven't medaled since 1984, when they claimed bronze in Los Angeles. The United States gained momentum this summer by placing third in the Champions Trophy event in June, and its No. 5 world ranking is its highest slot ever.