Asamoah Gyan kept African dreams alive with an extra-time winner to dump USA out of the World Cup.Landon Donovan's second-half penalty cancelled out Kevin-Prince Boateng's fifth-minute opener.And it was left to Ghana striker Gyan, who had worked tirelessly all night, to perform the heroics in the first period of extra time.It sealed the Black Stars a spot in the quarter-finals, where they will meet Uruguay for a place in the last four.With Ghana left as the only African side in the knockout stages, the hopes of the continent were on the players' shoulders.And they came flying out of the blocks, with Boateng quick to punish Ricardo Clark when the midfielder lost the ball on the halfway line.Boateng soon raced away and, with Jay Demerit struggling to recover, he unleashed a low drive into the bottom left corner.USA keeper Tim Howard will feel he should have done better as he was beaten at his near post.The Black Stars might have increased their lead after 18 minutes when a stinging free-kick was punched away by Howard.And Howard again had to be alive to gather another Boateng long-ranger on the half-hour mark.All the meaningful attacking was from Ghana and concerned USA coach Bob Bradley subbed midfielder Clark after just 31 minutes.With Maurice Edu introduced, USA picked up the tempo immediately and could have equalised soon after.Robbie Findley raced clear only to see his right-foot shot smartly saved by Ghana keeper Richard Kingson.But Howard was then back in action, pulling off a one-handed save low down from Udinese's Kwadwo Asamoah.Kingson denied half-time sub Benny Feilhaber with a brilliant block when one-on-one with the midfielder.And as USA pressed for an equaliser, young centre-back Jonathan Mensah paid the price for some naive defending.He brought down Clint Dempsey in the box and Donovan dispatched the spot-kick with perfection.With the scores level, both sides were uncharacteristically cagey and chances were few and far between.Michael Bradley had an opportunity to break the temporary deadlock when he beat the offside trap.He latched on to Jozy Altidore's smart through ball but his effort was straight at Kingson.Altidore then claimed a penalty when he was held back by John Mensah before firing wide, but his appeal was waved away by ref Viktor Kassai.Meanwhile, Gyan was showing great desire for Ghana, working hard in his lone role leading the front-line.And finally he was rewarded three minutes into extra time when he superbly kept his balance to blast past Howard.Wigan reserve keeper Kingson stayed strong under pressure to see off the late USA surge and seal Ghana's progress.Source: The Sun