Match ends, Ghana 1, USA 2.
John Brooks headed a late winner for USA in a dramatic finale to their opening Group G game against Ghana.
Clint Dempsey put USA ahead on 29 seconds with the fifth-fastest goal in World Cup history, cutting inside John Boye before sweeping home.
Ghana upped the tempo and equalised when Andre Ayew latched on to Asamoah Gyan's backheel to fire in a leveller.
USA looked tired but Brooks nodded in from six yards following a corner to give his side a winning start.
Centre-back Brooks reacted with a mixture of disbelief and delight, the Germany-born 21-year-old marking his Fifa World Cup debut and fifth cap in style.
The victory also gave USA a measure of revenge for being knocked out of the past two World Cups by Ghana.
They had looked to be tiring, and a winner seemed unlikely as Ghana dominated the second half and pulled themselves level.
But their tenacity was rewarded to leave the Black Stars precariously placed, with both teams having to face Germany and Portugal.
Ghana exited the World Cup four years ago in tears, when Gyan's missed penalty in the last minute of extra-time against Uruguay denied them the chance to become the first African side to reach the semi-finals.
If they were still nursing that pain, they did not show it as they sang and danced their way into the dressing room at the Estadio das Dunas.
But they fell behind within the first minute. Dempsey collected a Jermaine Jones pass on the left wing, cut inside right-back Boye and shot into the far corner.
Ghana struggled to mount a response as the USA consolidated their lead with a work-rate and organisation that kept their rivals at bay.
Indeed, Jurgen Klinsmann's side could, and maybe should, have extended their lead. Striker Jozy Altidore controlled a low, right-wing cross but his shot from 10 yards was blocked by Boye.
That was Altidore's last major act of the game, a hamstring injury seeing him replaced by Aron Johannsson.
USA centre-back Matt Besler also left the field injured, and his exit, combined with Ghana increasing the pace of their play, resulted in the Black Stars piling the pressure on Tim Howard's goal.
Most of the chances fell to Gyan, but he nodded high from 10 yards when unmarked before having another header tipped wide by Howard.
Gyan may not have scored, but he set up his side's equaliser as his lovely backheel teed up Ayew to shoot home with the outside of his right foot.
It seemed Ghana might have enough time to engineer a winner, but Hertha Berlin defender Brooks had other ideas, and his first international goal following Graham Zusi's corner proved decisive.
United States manager Jurgen Klinsmann:
"I said to the bench a few minutes before our winner, 'We are going to get some chances - we need to push and grind it out.' We trained over and over on set-pieces and it was well deserved.
"We have a great spirit and fight until the last minute. It was a grind but it was a wonderful one at the end of the day.
"There is stuff we need to improve. We had problems with keeping the ball."
Ghana coach Kwesi Appiah:
"What I can say is that it was a very tough game. Playing at this high level, any little mistake can cost you dearly.
"We didn't deserve the first goal against us and we did create a lot of chances.
"Unfortunately we could not take our chances and the US took theirs.
"Any loss of concentration can cost the team big time. I believe the first goal unsettled us a little bit but I never expected it to end this way."
- 12Larsen Kwarasey
- 17MohammedBooked at 30minsSubstituted forEssienat 71'minutes
- 11MuntariBooked at 90mins
- 7AtsuSubstituted forAdomahat 78'minutes
- 13J AyewSubstituted forBoatengat 59'minutes
- 10A Ayew
- 5BeslerSubstituted forBrooksat 45'minutes
- 11BedoyaSubstituted forZusiat 77'minutes
- 17AltidoreSubstituted forJóhannssonat 23'minutes
- Jonas Eriksson
- Shots on Target
Second Half ends, Ghana 1, USA 2.
Attempt missed. Sulley Ali Muntari (Ghana) left footed shot from outside the box is too high.
Sulley Ali Muntari (Ghana) is shown the yellow card for a bad foul.
Foul by Sulley Ali Muntari (Ghana).
Clint Dempsey (USA) wins a free kick in the defensive half.
Foul by Michael Essien (Ghana).
Jermaine Jones (USA) wins a free kick in the attacking half.
Attempt missed. Jonathan Mensah (Ghana) right footed shot from the centre of the box misses to the left following a corner.
Attempt blocked. Michael Essien (Ghana) header from the centre of the box is blocked. Assisted by Sulley Ali Muntari with a cross.
Corner, Ghana. Conceded by John Anthony Brooks.
Attempt blocked. Kevin-Prince Boateng (Ghana) right footed shot from the right side of the box is blocked. Assisted by Albert Adomah with a cross.
Goal! Ghana 1, USA 2. John Anthony Brooks (USA) header from the centre of the box to the high centre of the goal. Assisted by Graham Zusi with a cross following a corner.
Corner, USA. Conceded by Jonathan Mensah.
Goal! Ghana 1, USA 1. André Ayew (Ghana) left footed shot from the centre of the box to the bottom left corner. Assisted by Asamoah Gyan.
Foul by Daniel Opare (Ghana).
Jermaine Jones (USA) wins a free kick on the left wing.
Attempt saved. Clint Dempsey (USA) left footed shot from outside the box is saved in the top left corner. Assisted by Fabian Johnson.
Substitution, Ghana. Albert Adomah replaces Christian Atsu.
Substitution, USA. Graham Zusi replaces Alejandro Bedoya.