"Our guys were sensational today," said American captain Jack Nicklaus. "They finished the matches. They played great."
All six of the four-ball matches were close entering the final holes, but the United States dominated down the stretch to win five of them. The other match, which sent Phil Mickelson and Woody Austin against Vijay Singh and Mike Weir, was halved.
The United States is trying to defeat the International Team for the fifth time in seven tries.
David Toms and Jim Furyk recorded a 1-up victory over Ernie Els and Angel Cabrera; Lucas Glover and Scott Verplank were 1-up winners over Stuart Appleby and Retief Goosen; while Tiger Woods and Charles Howell defeated K.J. Choi and Nick O'Hern, 3 & 1.
Six foursomes matches are scheduled for Friday, with 12 more team matches set for Saturday and 12 singles matches for Sunday.