The Americans overcame a sluggish start in which they trailed in all four of the morning foursomes matches at the Medinah Country Club. They rallied to earn a 2-2 split in those battles and then won three of the four afternoon fourball meetings.
The 5-3 overall lead over their European rivals gave the United States players a solid start in their bid to win the biennial competition for only the third time in their last nine tries.
In addition to a 4-and-3 victory by Mickelson and Bradley over Luke Donald and Sergio Garcia, the Americans got a point in the morning from Dufner and Zach Johnson. That twosome defeated Francesco Molinari and Lee Westwood 3-and-2.
Mickelson and Bradley then went out in the afternoon and downed world No. 1 Rory McIlroy and Graeme McDowell 2-and-1. Simpson and Bubba Watson combined to win four of the first six holes and routed Paul Lawrie and Peter Hanson 5-and-4. Dustin Johnson and Matt Kuchar also won 3-and-2 over Justin Rose and Martin Kaymer.
Woods and Stricker were 2-and-1 victims of Rose and Ian Poulter in the morning and lost in the afternoon to Westwood and Colsaerts 1-up. Colsaerts, the first player from Belgium to play in the Ryder Cup, made eight birdies and an eagle to singlehandedly hold off the Americans. A 15-foot birdie attempt by Woods to win the final hole and halve the match slid by the left edge of the cup.
In the opening match of the morning, McIlroy and McDowell won the 18th hole to defeat Jim Furyk and newly-crowned FedEx Cup champion Brandt Snedeker 1-up.
The American cause looked bleak when the Europeans raced to a lead in each of the foursomes matches, but Mickelson and Bradley led the comeback. They won the final four holes of their match against Donald and Garcia and then captured the first three holes against McIlroy and McDowell in the afternoon.
Watson and Simpson, each with a major championship win this year, combined to birdie 10 holes during the course of their one-sided victory.
Eight more team matches will be played Saturday and 12 singles matches will be contested Sunday.
The first team to 14 1/2 points will win the solid gold chalice that serves as the trophy for this event. If the matches wind up tied, the Ryder Cup will remain with the Europeans since they won the event two years ago in Wales.