Sweden, which struggled up front for the second Group C game in a row, came away with a 1-0 win over North Korea that was worth a place in the last eight after the American victory.
The day's two winners have six points each, while North Korea and Colombia both have zero before the final round of matches and are eliminated.
Where Sweden missed chances for over an hour before it got a vital breakthrough, the two-time world champions were ahead within a dozen minutes after a fierce 25-meter drive from Heather O'Reilly into the left hand corner.
In a first week which has seen plenty of good goals, O'Reilly's was one to remember for its sheer force, which left goalkeeper Sandra Sepulveda helpless as the ball flew past her.
It brought the sellout crowd of 25,475 fans, including many Americans from nearby military facilities, to its feet.
"I took a couple of touches and just let it fly," O'Reilly said. Megan Rapinoe and Carli Lloyd also scored in a confident allround performance.
The Americans and Swedes meet in Wolfsburg on Wednesday to decide who finishes top of the group.
If Brazil wins Group D as expected, the winner of the clash will avoid facing Marta and her South American teammates.
Based on finishing skills, it should go to the United States, hands down.
When the U.S. players lined up to give a military salute to celebrate a goal, the Swedes got in a circle and did an intricate, joyful dance to mark theirs.
"It is our dance and I hope you guys get to see it more often," said captain Caroline Seger, who was yellow-carded for a run-in with the referee. The Player of the Match will miss Sweden's game against the U.S.
"I wanted to play that game. I want to play every game. But we are in the quarterfinal and that was our main goal," Seger said.
For Sweden to face Brazil or another Group D opponent doesn't matter to her.
"If you are the best you have to win against every team," she said. It was tough enough against a young North Korean side which included five teenagers, one as young as 16, in the lineup.
With tall strikers Lotta Schelin and Jessica Landstrom faltering, Sweden finally scored in the 64th minute when Linda Forsberg crossed into the middle and Therese Sjogran picked out the unmarked Dahlkvist for a simple finish from close range.
North Korea nearly equalized in the 73rd minute when Ri Un-hyang's header from a corner kick was cleared off the line by Sara Thunebro.