The Nordqvist-Pettersen win came in the eighth of the event's 28 matches, breaking a deadlock that existed after the first seven.
Nordqvist and Pettersen built a 3-up lead in a four-ball match against Americans Cristie Kerr and Michelle Wie after nine holes.
Kerr and Wie teamed for birdies on Nos. 10, 12 and 13 to square the match but a birdie at 15 returned the lead to the Europeans and a pair of pars ended the match at 2-and-1.
Paula Creamer and Morgan Pressel teamed for a 1-up victory for the United States and Caroline Hedwall and Sophie Gustafson were 5-and-4 winners in their four-ball match. The U.S. team of Christina Kim and Ryann O'Toole halved a match with Sandra Gal and Catriona Matthew.
Each team won two of the Friday morning foursomes matches, with Kerr and Wie teaming for one U.S. win and Creamer and Brittany Lincicome the other. The European wins were by the teams of Mathew and Azahara Munoz, and Gustafson and Pettersen.
The tournament continues with four foursome and four four-ball matches Saturday. There are 12 singles matches Sunday. The United States, as defending champion, needs 14 points to retain the Solheim Cup; Europe has to have 14 1/2 to win.
The United States holds an 8-3 advantage over the life of the competition.