Kristen Gillman led the charge for the US at Quaker Ridge Golf Club, winning both her matches.
A long-range birdie from the world's leading woman amateur golfer Lilia Vu made sure of a win against Sophie Lamb by two holes. Lilia Vu and Kristen Gillman, playing for Team USA, won their match outright 4 and 3.
"We have played good golf in spells, particularly on the first day, but at this level you have to have more consistency and at times we've just not performed as well as we would have liked".
"It allowed us to hit our putts fearlessly", Gillman said.
But then Gillman and Stephenson stepped in, and Li and Sophia Schubert claimed the final victory of the day 7&5 over Paula Grant and McWilliam.
The home team swept all three of the morning matches, with Mariel Galdano and Lilia Vu beating Alice Hewson and Annabell Fuller 2&1, and Lucy Li and Andrea Lee beating Lily May Humphreys and Shannon McWilliam 3&2.
"I just keep reminding them, stay focused, one shot at a time", said Team USA's Virginia Derby Grimes.
Stephenson, Gillman and the rest of the 'Bama squad are coming off a runner-up finish to Arizona in the NCAA Championships a few weeks ago.
In the other matches, top-ranked Lilia Vu defeated Sophie Lamb 2 up; Jennifer Kupcho, the NCAA individual victor this year for Wake Forest, beat Lily May Humphreys 2 and 1; Andrea Lee edged Alice Hewson 2 and 1; Lauren Stephenson beat Shannon McWilliam 2 and 1; 15-year-old Lucy Li defeated India Clyburn 5 and 4; and Mariel Galdiano held off Paula Grant 1 up.
It isn't likely to be an easy match for Kupcho and Gillman, ranked No. 2 and 8 in the World Amateur Golf Rankings, respectively.
Play resumes Saturday with a second morning round of fourball matches followed by afternoon foursomes matches.
Friday morning play began with three fourball matches.
GB&I captain Elaine Farquharson-Black, who had also captained the GB&I side to victory two years ago in Ireland, looked to put the result in perspective.
Jennifer Kupcho and Kristen Gillman, United States, def. Olivia Mehaffey and Sophie Lamb, Britain & Ireland, 3 and 2.
Mehaffey of Northern Ireland, the highest-ranked player on the GB&I team at No. 16, showed momentum can outweigh rankings when it comes to match play. The USA and GB&I teams halved the other two morning matches.
"Two years ago U.S. had every single player in the top-20 in the world, and we managed to win then", Mehaffey said. Looking back there's no way I was World No. 3, because the standard is just so different over here.
Schubert, the reigning US Women's Amateur champion, will contest the opening singles match of the final day against Mehaffey.
It was the first time the U.S. had achieved that feat in the singles in 1990, which was also the last time the U.S. won all four sessions of the match.