The USA edged Canada 1-0 in the SheBelieves Cup with a late Rose Lavelle goal, after Brazil beat Argentina 4-1 in the opening game in Orlando.
Canada lost goalkeeper Kailen Sheridan to injury after only 11 minutes, Stephanie Labbé replacing her and twice making diving saves to keep out long-range strikes by Lynn Williams.
Janine Beckie should have given Canada the lead early in the second half but Alyssa Naeher made a big save.
Christen Press came off the bench and soon shot into the side netting, while team-mate Lindsey Horan hit the bar from distance.
The breakthrough came with 11 minutes left, as substitute Rose Lavelle pounced on an attempted clearance to fire home.
Solo effort and two assists for Brazil Adriana
Argentina kept Brazil at bay for nearly half an hour but Aldana Cometti brought down Adriana, and Marta converted the resulting penalty.
Adriana also had a hand in the second goal 2 minutes after the interval, playing in Debinha to net past a wrong-footed Solana Pereyra.
It was 3-0 after 54 minutes, Adriana going on a run into the box and firing into the corner of the net.
Argentina got one back as Mariana Larroquette nodded a Yamila Rodriguez cross in off the post from a tight angle, although it was 4-1 when Cristine set up Geyse to score despite the keeper getting hands to the ball.
The SheBelieves Cup continues Sunday 21 February when the USA plays Brazil, followed by Canada faces versus Argentina.