Jackson Yueill redirected Sebastian Salcedo's cross for the go-ahead goal in the 60th minute to get the offense untracked, and second-half substitute Hassani Dotson added a pair of goals in a 4-0 victory on Sunday night at Guadalajara, Mexico, that advanced the U.S. to a qualification match on March 28.
Djordje Mihailovic, another second-half sub, had a goal and two assists for the U.S., trying to reach the Olympics for the first time since 2012.
Mexico leads Group A on goal difference over the U.S. and meets the Americans on Wednesday to determine matchups in the semifinals against teams from Group B, most likely Honduras and Canada. Semifinal winners qualify for the Olympics.
"We will want to beat Mexico. We will want to win this group," U.S. coach Jason Kreis said.
Kreis added that he was dismayed by his team's scoreless first half against the Dominican Republic.
"I felt that we were just way too cautious about the game," Kreis said. "We just weren't getting the job done. So for me it was mostly about positioning but also about intent and attitude."
American players did not generate sufficient attempts in the first half.
"The picture that they were presenting to us was extremely defensive -- five players in the back, nobody releasing in wide spaces and both of our fullbacks were extremely hesitant about going forward," Kreis said. "So it just didn't add up or make any sense, We needed to get those players really high. We needed to be looking for wide combinations."
Playing two days after his 24th birthday, Yueill scored just after Johnny Cardoso hit the crossbar. Substitutes were waiting on the sidelines at the time to come in for both Yueill and Cardoso.
Dotson, who replaced Cordoso, scored on a right-foot shot from just inside the penalty area in the 73rd minute off a short pass from Mihailovic, who came in for Salcedo. Dotson combined with Mihailovic again in the 78th, scoring on a right-foot shot from 8 yards, and Mihailovic scored on a sliding shot from 3 yards in the first minute of stoppage time off a cross from Benji Michel, another second-half sub.
"Hassani is a player that's coming into his own," Kreis said. "He showed up to this camp probably fitter than everybody else."
Olympic men's soccer qualifying is limited to players born Jan. 1, 1997, or later, and each team reaching the Olympics can add three wild-card players.
The U.S. failed to reach the 2012 and 2016 Olympics, a setback that preceded the senior national team's failure to reach the 2018 World Cup.
The U.S made six changes from the starting lineup in the opening 1-0 win over Costa Rica, when Jesús Ferreira scored in the 35th minute,
JT Marcinkowski started in goal in place of David Ochoa, Julian Araujo at right back for Aaron Herrera and Henry Kessler at central defender for Mauricio Pineda, joining central defender Justen Glad and left back Sam Vines.
Jackson Yueill was in defensive midfield, and Cardoso, Saucedo and Andrés Perea joined Jonathan Lewis in advanced midfield, replacing Dotson, Mihailovic and Michel. Ferreira again headed the attack, then was replaced by Sebastian Soto at the start of the second half.
The Dominican Republic, coming off an opening 4-1 loss to Mexico, started six teenagers as part of the youngest roster in the tournament.
In contrast to the U.S., the Dominican team did not have player names on their uniforms. FIFA's regulations say it is not compulsory for the name of the player to appear on his shirt during qualifying.
"Maybe it's the lack of experience. Maybe we were a little bit out of rhythm. Mentally I think we can do better," Dominican Republic coach Jonathan Himelfarb said. "But effort the first 60 minutes I was really proud, and definitely the future is bright for the Dominican Republic Football Association."