(CNN) -- World champions Italy had to come from a goal down to beat 10-man United States 3-1 in their Confederations Cup opener in Pretoria on Monday night.
Rossi made the difference as he came on after the halftime interval.
Landon Donovan put the U.S. ahead with a 41st minute penalty but the Azzurri hit back in style after the break with two goals from substitute Giuseppe Rossi and a Daniele De Rossi strike.
The win leaves Italy top of Group B alongside reigning Confederations Cup champions Brazil who beat Egypt 4-3 on Monday night.
Italy made a bright start and were boosted just after half hour mark when Ricardo Clark was sent off for a foul on Gennaro Gattuso.
But it did not stop the U.S. from taking the lead near halftime as Joze Altidore was fouled by Giorgio Chielleni in the penalty area.
LA Galaxy star Donovan scored his 40th international goal from the spot.
Italy coach Marcelo Lippi brought on former Manchester United man Rossi in the second half and within moments of coming on he had scored with a blistering 30 meter drive to beat Tim Howard.
De Rossi scored the second in the 72nd minute as his shot bounced ahead of Howard and found its way into the right corner of the net.
Villarreal striker Rossi wrapped up the win with his second in injury time.