Asamoah Gyan kept the African flag flying at the World Cup with a spectacular left-foot strike in extra-time to take Ghana through to their first quarter-final.

It was the second time in successive World Cups that Ghana had defeated the United States, having effectively dumped them out of the tournament four years ago by beating them in the final group game.

Gyan's goal, after 93 minutes, was worthy of winning any game after he outmuscled USA captain Carlos Bocanegra to blast his shot past goalkeeper Tim Howard.

It settled a contest that was level at full time after Landon Donovan's second-half penalty cancelled out a fifth-minute strike from Kevin-Prince Boateng.

It was just reward for Ghana's talent and power in a dramatic encounter at the Royal Bafokeng stadium and the sole surviving African nation must now fancy their chances of creating an even bigger ripple at this tournament, with Uruguay awaiting them in the last-eight.

Former president Bill Clinton had turned up to support the USA and was sitting for a time next to Rolling Stone Mick Jagger, who might well have made his plans expecting England to have topped Group C and been playing down the road from their training headquarters.

The USA had stymied those plans by finishing first but it was clear they were going to be stretched by Ghana's pace.

The Black Stars could hardly have made a more stunning start.

Portsmouth's Boateng picked up the ball just inside his own half, slalomed past three defenders and unleashed a left-foot shot which flew past Howard.

It was Ghana's first goal at this World Cup from open play, having beaten Serbia and drawn with Australia in the group phase courtesy of two penalties.

But Boateng's strike demonstrated their firepower and they might have added to their lead with Gyan, who plays for French club Rennes, a constant threat.

So superior were Ghana in that first period that after 31 minutes a concerned USA coach Bob Bradley substituted midfielder Ricardo Clark, who had received an early booking, and brought on Maurice Edu.

The Americans picked up the tempo immediately and could have equalised after 35 minutes when Robbie Findley raced clear only to see his right-foot shot smartly saved by goalkeeper Richard Kingson.

The USA came out after half-time, however, with a more determined, more attacking attitude and the excellent Kingson was straight into the action, forced to pull off a splendid save from Benny Feilhaber.

With Fulham's Clint Dempsey at the heart of their good work the Americans surged forward and they received their reward after 62 minutes.

Dempsey was the architect, weaving his way through the Ghana defence into the penalty area where he drew the challenge and was brought down by defender Jonathan Mensah.

Hungarian referee Viktor Kassai pointed to the spot and Los Angeles Galaxy's Donovan stepped up to slide home his third goal in four matches.

The USA dream appeared back on, especially as they are a team who make a habit of stirring comebacks.

They had their chances. Jozy Altidore might have done better when clear after 80 minutes but he spooned his effort wide under pressure from a defender.

So to a frantic extra-time and Gyan's stunning strike which sent the USA home and Ghana into ecstasy.

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