INCHEON, South Korea (AP) Phil Mickelson and Zach Johnson won the only match that reached the 18th hole and finished off another dominant day for the Americans in the Presidents Cup on Thursday.
The rest of the foursomes matches were not much of a contest, and the Americans built a 4-1 lead after the opening session.
The South African duo of Louis Oosthuizen and Branden Grace won the only match for the International side.
It was the fifth straight time in the Presidents Cup that the United States took the lead, and its largest since a four-point advantage in 2007.
The International team hasn't won since 1998, and this wasn't the start it wanted.
Jordan Spieth and Dustin Johnson proved a formidable partnership, while Jimmy Walker and Rickie Fowler won the shortest match.