1
general::
Phrase(s): prevail (up)on someone or something (to do something)
to appeal to someone or a group to do something. (Upon is formal and less commonly used than on.) • I will prevail upon her to attend the meeting. • I prevailed on the committee to no avail.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Successfully persuade or influence, as in They prevailed on me to speak at their annual luncheon. This term uses prevail in the sense of "exert superior force." It replaced prevail with in the mid-1600s.
American Heritage Idioms