Ghana recovered from defeat in their opening group game by Italy to clinch a place in the last 16 with victory over the USA in Nuremberg.
Haminu Dramani fired Ghana ahead after robbing Claudio Reyna, but Clint Dempsey's first-time shot levelled.
Stephen Appiah restored Ghana's lead from a controversial penalty awarded against USA defender Oguchi Onyewu.
As USA pressed for an equaliser, Brian McBride sent a diving header against the post.
Referee Markus Merk stamped his early mark on the game, booking Eddie Lewis and Michael Essien inside the first six minutes.
With plenty at stake there was no quarter, and Lewis needed treatment for an eyebrow cut caused by John Mensah's stray elbow.
But Dramani raised Ghana's hopes of a place in the knockout stages by firing them ahead.
Dramani's shuddering challenge caught Reyna in possession and he made ground before curling his shot around Kasey Keller's dive.
Essien's role in the battle for midfield supremacy was pivotal to Ghana's hopes and he won the ball to release the pacy Razak Pimpong who pulled his shot wide.
USA's build-up play tended to be deliberate, allowing Ghana time to get bodies behind the ball but the direct route proved effective when McBride rose to flick the ball on for Landon Donovan who sliced his shot wide.
The Americans suffered a blow when playmaker Reyna limped off but they made light of if when they levelled just before half time.
DaMarcus Beasley intercepted Derek Boateng's pass and curled a delicious cross into the path of Dempsey who crashed home a first-time shot.
But referee Merk added one more twist to the first half with a controversial penalty award, penalising Onyewu who appeared to win a clean header as Pimpong collapsed dramatically, allowing Appiah to despatch the spot-kick.
Donovan swung in a dangerous free-kick as USA piled on the pressure at the start of the second half but Ghana showed their threat on the break and Keller had to claw away a powerful shot from Matthew Amoah.
For all their possession the Americans showed little guile and wit to break Ghana down in a game that continued to be dominated by referee Merk's whistle.
USA's luck was out as McBride dived full-length to head Lewis's cross against the post before Onyewu headed inches over the bar from a corner.
The Americans' view they were victims of some debatable refereeing were increased when Mensah was only shown a yellow card for a dreadful, cynical foul on substitute Bobby Convey.