NATAL, Brazil » It began with the magical. It ended with the miraculous.

John Brooks, a 21-year-old German-American who was playing in his first competitive game for the United States and who was on the field only because a starting fullback was hurt, powered a fierce header into the net in the 86th minute Monday to give the U.S. team a stunning 2-1 victory over Ghana in its first match of the tournament.

Afterward, Brooks said that he dreamed nearly the exact situation two nights ago, the only difference being that, in his imagination, he scored in the 80th minute. He did not seem particularly bothered by reality’s six-minute delay.

"It was my first dream," he said softly, "hopefully not my last."

Brooks’ header was the dramatic coda to an evening that was a jackhammer of emotions. It opened with exuberance from the Americans after Clint Dempsey scored inside 30 seconds. That was followed by about 80 minutes of nervy, anxious nail-biting as two key U.S. players were lost to injury and the Ghanaians pounded at the United States goal. Then came a few moments of disappointment after Ghana tied the game. And, finally, there was Brooks, rising to meet Graham Zusi’s corner kick and covering the U.S. with the warm glow of an upset victory.

The Americans still have a considerable road to

navigate to reach the knockout rounds with group games yet to play against Portugal and Germany, but any hope of advancement was predicated on a positive result here. And the United States got one.

"The response after they scored was really good," midfielder Michael Bradley said. "You looked around and still felt like there was more in it."

When it was over, coach Jurgen Klinsmann, who had not hesitated to liken this game to a final in terms of its importance, ran onto the field, a smile wide across his face. The Ghana players, aware of how critical three points were, sank to the ground in disbelief.

"The feelings are just incredible," U.S. defender Matt Besler said.

It was that way from the start. Just moments after the game kicked off, Dempsey, the U.S. captain, saw a pass come his way and let it run, stepping over the ball with his foot before tapping it forward with the inside of his right heel. It was a stylish move, a little bit of class. Dempsey cut to the inside and, with a quick finish, suddenly stroked the ball past the goalkeeper and in off the inside of the far post as Klinsmann and the entire U.S. bench erupted.

"I saw that there was space," Dempsey said, "and I just tried to hit it as hard as I could."

But the Americans could not maintain that pace. In truth, most of the rest of the game was maddening for the U.S. as Ghana bossed the ball around the field. Frustration turned to sadness, too, when Jozy Altidore, one of Klinsmann’s top strikers, looked as if he suffered a serious leg injury.

Altidore reached down and grabbed the back of his leg as he sprinted for a ball down the sideline in the 21st minute. That telltale motion — accompanied by Altidore’s waving his other hand in the air in submission — is almost always a sign of real pain. Altidore was taken off on a stretcher, his World Cup participation now murky because of a strained hamstring.

"I was crushed," Altidore said. "I knew right away I couldn’t continue. It was the worst feeling."

Things did not improve as the minutes passed. The Ghanaians, who eliminated the United States in each of the past two World Cups, hammered on the Americans. Kyle Beckerman was floored by an elbow to the head from Mohammed Rabiu (who was cautioned). Dempsey went down, blood pouring from his nose, after taking a shin to the face from John Boye (who was not).

Dempsey played the rest of the game despite struggling to breathe through his nose, saying afterward that he was "coughing up blood a little bit."

Alejandro Bedoya also looked bothered by a leg injury and so, too, did Besler, one of the two starting central defenders. With Ghana controlling possession and pushing, Klinsmann did not want to risk a gimpy defense; he pulled Besler at halftime as a precaution but did not insert Omar Gonzalez, a veteran defender. Instead, he opted for Brooks, one of several dual-national players that Klinsmann has recruited and a player who, until he stepped on the field to start the second-half, still had the option, under FIFA’s eligibility rules, of switching his allegiance to Germany.

U.S. fans need not worry about that now. Brooks played stoutly in defense as the U.S. back line, anchored by goalkeeper Tim Howard, held off the Ghanaians until the 82nd minute. That was when Andre Ayew finished off a pretty passing sequence and finally beat Howard at the near post with a twisting shot from close range.

Deflated as the Americans surely were, they also knew that a tie, earning them a point, was still a good result. But Brooks wanted more. And when Zusi’s penetrating corner swung in, the 6-foot-4 Brooks met the ball ferociously, blasting it down and bouncing it past Adam Kwarasey in Ghana’s goal.

Brooks ran toward the corner flag and collapsed, as if he could not believe what had happened.

"If you score after just one minute," Klinsmann said, "you think there can’t be anything better than that."

But there was. It was something from a dream.

Natal, Brazil

First half—1, United States, Clint Dempsey 1, 1st minute.
Second half—2, Ghana, Andre Ayew 1, 82nd. 3, United States, John Brooks 1, 86th.
Shots—Ghana 21, United States 8.
Shots On Goal—Ghana 8, United States 7.
Yellow Cards—Ghana, Mohammed Rabiu, 30th; Sulley Muntari, 90th, injury time.
Offsides—Ghana 5, United States 1.
Fouls Committed—Ghana 10, United States 12.
Fouls Against—Ghana 12, United States 10.
Corner Kicks—Ghana 7, United States 3.
Referee—Jonas Eriksson, Sweden. Linesmen—Mathias Klasenius, Sweden; Daniel Warnmark, Sweden.

GROUP G

Monday
Germany 4, Portugal 0
United States 2, Ghana 1
Saturday
At Fortaleza, Brazil
Germany vs. Ghana, 9 a.m.
Sunday
At Manaus, Brazil
Portugal vs. United States, noon
June 26
At Recife, Brazil
Germany vs. United States, 6 a.m.
At Brasilia, Brazil
Portugal vs. Ghana, 6 a.m.

Sam Borden, New York Times

© 2014 The New York Times Company