Five players earned their first cap, including a pair of collegians, Andi Sullivan, who started, and sub Ashley Hatch, a senior at nearby BYU. Chicago Red Stars defender Casey Short also started and Flash defender Abby Dahlkemper came on in the second half.
With her first touch in a U.S. uniform, Williams stole an errant backpass and scored on a breakaway. Tobin Heath and Christen Press, both 2015 U.S. World Cup champions and 2016
Olympians, and Samantha Mewis, a 2016 Olympic alternate and another of the young Flash players Jill Ellis called in for the Switzerland series, scored the other goals.
The game also marked a change in formation as Ellis employed a 3-5-2 with Allie Long, normally a center midfielder, in the back flanked by co-captain Becky Sauerbrunn and Emily Sonnett.
The USA and Switzerland will play the second of their friendlies on Sunday at U.S. Bank Stadium in Minneapolis.
Oct. 19 in Sandy, Utah
USA 4 Switzerland 0. Goals: Williams 46, Heath 61, Press 69, Mewis 76.
USA -- Naeher; Sonnett (Press, 46), Long (Dahlkemper, 72), Sauerbrunn; Heath (Hatch, 75), Sullivan (Mewis, 75), Brian, Horan (Williams, 46), Short; Lloyd (O'Hara, 64), Dunn.
Switzerland -- Thalmann; Kuster, Kiwic, Abbe, Maritz; Mauron (Mueller, 62), Moser, Zehnder, Aigbogun; Willi (Deplazes, 46), Calligaris.