The 25-year-old Massachusetts native was accompanied by fiancé Roberto Martinez - who served as catcher - to game two between the Red Sox and the Rays.
Speaking to Red Sox Gameday Live before her throw, she said: "I'm not [nervous]. Nothing makes me nervous, but I don't know, we'll have to see what happens when I get out there. If I throw it in the dirt I'll blame my nerves!"
Martinez, who played baseball in college, added that it was a "dream come true" being at Fenway Park for the first time.
Fedotowsky also wrote about the event on her Facebook account, saying: "Out of everything I've been able to do as the Bachelorette, this is definitely one of the coolest :) Go SOX! (sic)"
She also said that she and Martinez have been "exploring" her Massachusetts hometown together and that she had been to see an old college professor and spoken at Clark University earlier that day.
