Euro 2012 qualifiers Italy crashed to their second straight home defeat with a disappointing 1-0 loss against the United States.
Fulham striker Clint Dempsey drove in the second -half winner as the Americans earned a historic first win over the Italians.
The Azzuri dominated large spells of the Genoa friendly but were denied by some excellent goalkeeping by Everton stopper Tim Howard.
And it was a sweet result for US boss Jurgen Klinsmann, who saw his dream of leading his native Germany to a home World Cup victory in 2006 ruined by the Italians in the semi-finals.
Italy coach Cesare Prandelli had emphasised the importance of the game as he looked ahead to this summer's tournament in Poland and Ukraine.
He was keen to test alternatives in attack with Antonio Cassano, Giuseppe Rossi and Manchester City's Mario Balotelli missing the game.
The hosts made much of the running in a keenly-fought first half and had the ball in the American net on 25 minutes when Alessandro Matri's shot was ruled out for offside.
Denied
Howard denied further efforts from Domenico Criscito and Thiago Motta before the Italians were made to pay their inability to convert possession into goals shortly after the restart
Former Hull striker Jozy Altidore superbly controlled a left-wing cross to set up Dempsey, who made no mistake from 10 yards for the 55th-minute winner.
Italy could have salvaged a draw but wasted three late chances through substitutes Giampaolo Pazzini, Fabio Borini and Riccardo Montolivo.