The Europeans looked to be on top early in the round, coming back from one down to lead one up after six holes.
Donald was twice denied by the rim of the cup as Europe threatened to run away with the match.
However, the impetus shifted towards the US team, with Mickelson and Bradley starting to surge.
Garcia pushed a four-foot putt wide of the hole on the 14th green, which gave the Americans the chance to get the first point on the board at the next hole.
They pounced on that opportunity, as Bradley sunk a marvellous effort to put them within touching distance and spark the crowd into raptures.
Donald had left Garcia with a pitch from the greenside bunker, which he had to somehow hole to keep the match alive.
The Spaniard could not conjure a miraculous shot and it was David Love III's men who registered the first point of the 2012 Ryder Cup.