Following a 2-2 split in the morning foursomes at Robert Trent Jones Golf Club, the US went 2-2 in fourballs, leaving Europe needing a record-equaling comeback on Sunday in order to lift the Solheim Cup for a record fourth consecutive time.
According to Elias Sports Bureau, the largest lead overcome entering the final 12 singles matches is four points, with the US having won the 2015 Solheim Cup by a point after trailing Europe 10-6 going into the singles session.
"The Europeans played a lot better today, and that showed, but really, really happy with the day, and to keep the same lead," said US captain Stacy Lewis, whose team needed to reach 14-1/2 points to reclaim the Solheim Cup.
"We're going to go try to win as many points early as we can and try to get this thing done."
The US led 8-4 going into the fourball session where Rose Zhang and Andrea Lee grabbed the first point of the afternoon with a 6&4 win over Europe's Linn Grant and Celine Boutier.
The American pair birdied the opening hole and never looked back as Lee padded their already sizeable lead when she chipped in from a greenside bunker at the par-four 13th to put them 5-up before Zhang closed it out with an eagle at 14.
Moments later Alison Lee and Megan Khang earned the second US point of the afternoon with a 4&3 win over Swedish pairing Anna Nordqvist and Madelene Sagstrom.
Lee put the US ahead early in her match when she spun in a wedge from 86 yards for eagle at the par-four second which, as per a deal they made on that same hole, led to her caddie and the caddie for Khang to rip off their shirts in celebration.
But Europe refused to go away, and so a 2&1 win by Emily Pedersen and Carlota Ciganda over Ally Ewing and Lexi Thompson trimmed the lead before Charley Hull and Georgia Hall secured a point with a 2-up victory over Allisen Corpuz and Lilia Vu.
In the morning session, the hosts trailed three of the four matches at one point as Europe looked ready to make a move, but the United States rallied late to earn a split.
Lauren Coughlin became the third American Solheim Cup rookie to win each of her first three matches as she and Thompson beat Maja Stark and England's Hall 4&3 for the day's first point.
Moments later, Europe struck back as Nordqvist and Boutier beat Vu and Sarah Schmelzel 4&3 in a match the visitors took control of from the first hole.
Nelly Korda and Corpuz reached the turn staring at a 2-down deficit but the American duo managed a 1-up victory over Pedersen and Ciganda to become the first tandem in Solheim Cup history to win four consecutive foursomes matches.
"I feel like every single time you play with Nelly it's kind of like, 'Hey, it's going to turn around at some point, just be patient and keep playing and keep playing the way that we have,'" said Corpuz.
Europe's Esther Henseleit and Hull were 3-up after eight holes but squandered that lead and needed a birdie at the last to secure a 1-up win over Ewing and Jennifer Kupcho.
