The rest of the foursomes matches were not much of a contest as the Americans built a 4-1 lead after the opening session.
It was the fifth straight time the Americans have taken the lead in the opening round of this one-sided contest, and the three-point lead was their largest margin since they had a four-point lead in 2007 in Canada.
The Americans are going for their sixth straight victory, and after one day at the Jack Nicklaus Golf Club Korea, there was a familiar feel to the event.
The South African duo of Louis Oosthuizen and Branden Grace won the only match for the International side, taking advantage of a few poor shots by Matt Kuchar to seize control on the back nine for a 3-and-2 win over Kuchar and Patrick Reed.
It was the first point for Grace, who went 0-4 two years ago at Muirfield Village in Ohio.
''I know we're behind,'' Grace said. ''But one point is better than none.''
Even so, this was another strong display by the U.S., which never trailed in the other four matches and has lost only one time in the Presidents Cup since it began in 1994.
Rickie Fowler and Jimmy Walker, who halved all three of their team matches at the Ryder Cup last year, finally got their first full point in the shortest match of a short day. They ran off three straight birdies early and had three more on the back nine to win, 5 and 4, over Anirban Lahiri of India and Thongchai Jaidee of Thailand.
Perhaps the most pivotal match was the first one. Bubba Watson and J.B. Holmes, two of the longest hitters in golf, never trailed after a birdie on the second hole, though it was tight on the back nine against Australia's Adam Scott and Japan's Hideki Matsuyama.
By then, the Americans were ahead in three other matches, and the International team could have used a win to at least keep it close. The Americans were 1 up when Scott missed a putt to win the hole, and the U.S. pulled ahead 2 up when Matsuyama left a downhill birdie attempt short and Holmes rolled in an 8-foot birdie on No. 15. Holmes rolled in a birdie on the 16th from about 15 feet to close out a 3-and-2 win.
Jason Day tried to give the International side at least a little momentum going into Friday. Day and Australian compatriot Steven Bowditch were 2 down to Mickelson and Johnson with two holes to play when Day poured in a 40-foot birdie putt to send the match to the 18th. Bowditch hit a long iron to about 18 feet for an eagle chance, though Mickelson pounded his tee shot so far that Johnson was able to stick his approach to 10 feet. Day narrowly missed the eagle putt, and conceded the eagle to the Americans for a 2-up win.
Mickelson, who has never missed a Presidents Cup, tied a tournament record with his 11th foursomes victory. Tiger Woods also has 11 foursomes wins.
The format was changed this year to eliminate one match a day and reduce the total points from 34 to 30. That didn't help the International side. The way Thursday went, it might have kept the score from being worse.