They hammered the worldwide teams on the back nine to go unbeaten in fourballs and build an 8-2 lead, the largest margin after two sessions since the Presidents Cup began in 1994.
Also scoring points for the USA were Brooks Koepka and Dustin Johnson, who birdied the final two holes for a 3&2 decision over Australia's Adam Scott and Venezuela's Jhonattan Vegas, and Rickie Fowler and Justin Thomas with a 3&2 victory over South Africans Louis Oosthuizen and Branden Grace.
Dustin Johnson and Brooks Koepka, United States, def. Adam Scott and Jhonattan Vegas, International, 3 and 2.
The final match up of the day featured Australians Jason Day and Marc Leishman against the American team's Phil Mickelson and Kevin Kisner, in what turned out to be a closely-fought battle right to the final hole.
There are four foursomes matches followed by four four-ball matches tomorrow, and then 12 singles matches on Sunday.
Hoffman and Chappell are Presidents Cup rookies and promptly earned a point.
Hope remains for the global side thanks to Branden Grace and Louis Oosthuizen, who secured a hard-fought 2&1 victory over Daniel Berger and Brooks Koepka.
"This reminds me a lot of the 2008 Ryder Cup team, when we were finally able to win at Valhalla", he said.
FedEx Cup champion Justin Thomas made a fine debut in the event as he and Rickie Fowler ran riot against Charl Schwartzel and Hideki Matsuyama. It was the first time in 10 years the worldwide did not win a match in a session.
Hoffman and Chappell were three up after the first four holes, before birdies at eight and nine saw them take a five hole lead into the back nine.
The International team can be backed at 25/1 for a remarkable win and the tie at 15-15 is available at 20/1. A par by the Amercians was good enough to win the 14th, and a final 8-foot birdie putt by Reed on the 15th closed out the match.
Needing to mount an early charge to battle back into contention, the worldwide team instead got the day off to a foreboding start when Leishman sent his opening tee shot into the water in the alternate shot event handing Spieth and Reed a 1-up lead.
And, finally, fellow rookie Kevin Kisner teamed with Phil Mickelson to claw out the day's final point for Stricker, a flag that just an hour earlier seemed improbable and likely put the finishing touches on an overmatched and seemingly out-of-answers global team.
Justin Thomas of the U.S. Team and Rickie Fowler of the U.S. Team walk on the eighth hole during Thursday foursome matches of the Presidents Cup at Liberty National Golf Club on Friday in Jersey City, New Jersey.
"We've got to just keep our heads up and try to inch our way at points". Lahiri and Schwartzel won only one hole when both players stuffed tee shots on the par-3 10th to 3 feet. "The South Africans built a 2 UP lead thru six holes, including circles at holes 2 and 6, with the Americans winning just the fourth with birdie-4, but they lost holes 7-9, beginning with a 3-putt bogey at 7 from 59'9" and a sloppy double bogey-6 at 8.