Bolas won over Ford Palmer (3:59.30) and Ashley Schneider beat out Heather Wilson (4:33.04) and Ashley Higginson (4:34.32).
Men's field is led by Jordan McNamara, Pat Casey and Mac Fleet while the women's has Heather Kampf, Gabe Grunewald and Ashley Higginson.
The final two sections of the men's 1500 and the men's and women's 5,000s were all cancelled due to a thunderstorm, which meant no races for Robby Andrews, Galen Rupp or Kara Goucher. Manzano won a slow 1500 in 3:38.96 over Wheating (3:39.56), while Rowbury (1500) and Symmonds (800) both had runners go down directly in front of them, messing up their races.
Mark Wetmore's two biggest stars will make their season debuts - Jenny Simpson (800) and Emma Coburn (1,500) - while Kara Goucher (5,000) will run her first track race since 2013 and Mary Cain will look to regain her "teen phenom" label.
Stephanie Charnigo won the mile in 4:31.78 over Ashley Higginson (4:32.31). John Travers won the men's race in 3:59.62.
Coburn ran a very impressive 9:19 in 84-degree heat and now owns three of the top six times in the world this year. Ashley Higginson ran a big PR of 9:27 for second.