The United States, two-time defending champion in the competition contested among the countries of North and Central America and the Caribbean, is 23-0-1 in Gold Cup group play.
The Americans are 2-0 and lead Group B going into their final first-round match against Haiti on Saturday in Foxborough, Mass., where a draw will be enough to clinch the group and move into the quarterfinals.
Quaranta took a short pass from Charlie Davies, who replaced Freddy Adu in the 64th minute, at the top of the penalty box and fired in his first goal for the national team. Four minutes later, Ching put in his header from the goal box to seal the victory.
It is nearly an entirely different roster from the U.S. team that made a surprise run to the Confederations Cup championship game last month; most regulars were given a rest for the Gold Cup.
The Americans last played Honduras on June 6 in a World Cup qualifying match, but the only American who was dressed for that game and Wednesday's match was Benny Feilhaber, who came on in the 64th minute.
The crowd of 26,079 spectators at RFK Stadium had a pro-Honduras bent, although cheers greeted both teams' offensive chances.
Both squads had several opportunities before the United States broke through.
In the 15th minute, Quaranta had a header go wide left of the goalpost. Adu started the sequence with a nifty heel kick to Robbie Rogers, who took the ball deep into the left side of the penalty area before sending a cross to Quaranta in the middle.
He dived and sent the header toward the post.
Honduras had a golden opportunity in the 30th minute. Walter Martinez had a breakaway with only goalkeeper Troy Perkins to beat, but his shot was just wide, hitting the right side of the goal netting.
HAITI 2, GRENADA 0
In Washington, Fabrice Noel scored in the 14th minute and James Marcelin added a goal in the 78th in Haiti's victory.
The win was Haiti's first in the Gold Cup since 2002. Haiti is 1-1 in Group B.
Grenada is the group's lone winless team going into Saturday's game against Hon-duras.
Noel's goal came off a free kick by Brunel Fucien into a crowd in the middle of the penalty area. Noel deflected it into the net.
STRIKE THREATENS 'CUP'
JOHANNESBURG -- South African construction workers went on an indefinite strike Wednesday at stadiums being built for the 2010 World Cup -- a move that could derail Africa's historic first World Cup tournament.
The strike could delay completion of flagship projects such as the Soccer City stadium in Johannesburg and stadiums in Cape Town and Durban. Other stadiums in smaller towns have also been affected.
The venues need to be completed by December to meet deadlines set by the game's ruling body FIFA before the tournament kicks off in June 2010.