Starting the closing foursomes two behind overnight leaders Ireland,Kuchar and Woodland carded six birdies and a bogey at the Mission Hills Resort on Hainan Island to finish 24 under-par.
England raced up the leaderboard as Ian Poulter and Justin Rose returned a 63 that featured an eagle, eight birdies and a bogey to finish 22 under. That left them tied for second with Germany, who posted a 69.
Irish duo Rory McIlroy and Graeme McDowell, meanwhile, could only produce an even-par 72 as they missed out on the last day for the second consecutive time, after finishing runners-up to Italy in 2009.
The tone was set when they three-putted the opening hole and their score of 21 under par left them in a tie for fourth with Scotland, Holland and Australia.
South Africa, who were joint second with the USA and Germany on Saturday night, fared even worse. Their recent major winners Charl Schwartzel and Louis Oosthuizen tumbled down the 28-team leaderboard into 12th place with a highly forgettable 74.
Kuchar and Woodland were understandably delighted to earn a 24th World Cup triumph for the USA and said the finish to Saturday’s round had laid the foundations.
“We took momentum from the last hole on Saturday,” said Woodland. “Making par there gave us a boost for the final round, and then we got two birdies in a row to start with.
“We came here hoping to have some fun. We set a goal out to win and that’s what we came here to do. We played phenomenal, especially today.
“We got off to a hot start early, played solid on the back, and really we were not in trouble in the back at all. It was a good day.”
Kuchar, who was the third highest ranked player in the field, credited Woodland for their winning partnership.
“When I got selected to represent the United States in the World Cup, I chose Gary Woodland, thinking that he would team up well with me. I have no doubt that he was the best player in the field,” said the world number 10.
“For me, it was a lot of riding his coat-tails, trying to keep encouraging him to keep it going, because he played some great golf. And I’m fortunate and really, really excited that I picked him.”
Kuchar also revealed that they had received a text message from Phil Mickelson before the final round, saying they should go out and be aggressive and win it for the United States. “That was a real motivator,” added Kuchar.
Meanwhile, joint runners-up Martin Kaymer and Alex Cejka of Germany were left to rue a missed chance on the par four 16th.
Having reached the turn in 34 after birdies on the second and ninth, they could have narrowed the Americans’ lead to one if they had birdied 16 but the chance went begging.
“I was a little frustrated about today because we had good chances and I missed a lot,” said Kaymer.
“16 was a big, big chance for us to put the Americans under pressure. They would have seen our score on 17 when they walked up to the green, they would have seen we are only one shot behind them,” said the world number four.
England, rated as one of the pre-tournament favourites, could only reflect on what might have been after they failed to take advantage of the low scoring fourballs format, posting 66 and 68 in the first and third rounds.
“I felt like today was a bit about coming out and playing for pride,” said Rose. “You always have pride when you are playing for your country but it was about restoring individual pride for ourselves, really. Both fourballs days were uncharacteristic for us, and today was fun.
Poulter added: “We were a little subdued last night. It was disappointing to shoot four-under par in fourballs, and to go and shoot nine-under par today and actually leave shots on the golf course sounds very silly to say, but it’s a fact.”