FRISCO, Texas -- Crystal Dunn tied a national team record with five goals and U.S. women routed Puerto Rico 10-0 on Monday night to win Group A in the CONCACAF qualifying tournament for the Rio Olympics.
The top-ranked Americans scored three times within 1:56 during the second half and outshot Puerto Rico 32-1.
The U.S. can clinch one of the 12 slots in Brazil with a win in its CONCACAF semifinal game Friday in Houston. It will face the runner-up of Group B, which will finish play Tuesday. Canada is expected to win that group with Guyana or Trinidad & Tobago finishing second.
The U.S. remained unbeaten in all-time CONCACAF qualifying play at 16-0-1, having scored 91 goals and allowing four.
The tournament is the Americans' first competitive play since winning last summer's World Cup in Canada. They have won three straight Olympic titles and four of the five that have been staged in women's soccer.
Group A's other semifinalist is Costa Rica, which edged Mexico 2-1 in Monday's first game at Toyota Stadium.
Dunn's scores came in the sixth, 21st, 62nd, 85th and 87th minutes. She had five career goals going into the game.
The other five goals came from Carli Lloyd (on a penalty kick), Kelley O'Hara, Christen Press, Samantha Mewis (her first career score) and on an own goal.
U.S. coach Jill Ellis' opening lineup included eight players who didn't start either of the two previous group games and only five players who appeared in last summer's World Cup. The lineup was drastically changed since the team had already clinched a semifinal spot, was playing for the third time in five days and faced an opponent ranked No. 108.
Alex Morgan played only the second half, substituting for Lloyd. Goalkeeper Hope Solo was among the regular starters rested.
The newcomers including Mallory Pugh, 17, the youngest American woman to start a qualifying match. Pugh assisted on Dunn's first goal and was tripped in the 18th minute, leading to Lloyd's penalty kick.
Alyssa Naeher earned the shutout in her first CONCACAF qualifying appearance.
It was Lloyd's 85th career international goal and 11th in Olympic qualifying, three off Abby Wambach's U.S. record.
O'Hara's score came on a back heel near the goal line in the 45th minute off a cross from Stephanie McCaffrey.
Puerto Rico made its first appearance in the CONCACAF qualifying tournament and had never previously faced the United States at the senior level. It was outscored in its three matches 25-0.
This U.S. roster features only 13 of the 20 players who were on the World Cup team. Christie Rampone and Megan Rapinoe are injured, and Amy Rodriguez and Sydney Leroux are pregnant and will miss the Olympics.