Boynton hit five of Florida's 14 3-pointers and added five assists as part of the Gators' second straight victory. He had reached 22 points in a game on three previous occasions this season.
Florida held Rider scoreless for 5:30 late in the first half on its way to a 43-27 advantage at intermission.
Bradley Beal added 18 points for Florida (7-2) while Patric Young and Erving Walker both had 12. Walker went 4-of-6 from 3-point range.
Jeff Jones scored 18 points for Rider (1-9), which posted its only victory Nov. 21 against Howard.
The Gators were the lone nationally-ranked team in action on Friday's major college basketball schedule.