After Khwan Fore's 3 brought the Spiders within 59-57 with 3:54 left, Javon Bess and Jalen Johnson made back-to-back layups, Hasahn French and Foreman each made 1 of 2 free throws and Rob made two free throws and Saint Louis (8-8, 1-2 Atlantic 10) led 67-59 with 50 seconds left.
The Billikens led 27-26 at halftime before Richmond used a 17-6 run and led by 10 after Jacob Gilyard made a pair of free throws with 13:50 left. More than four minutes later, Johnson's 3-point play capped a 14-4 run to knot the score at 47. French's layup with 7:48 to go put Saint Louis ahead for good. French had 14 points and nine rebounds.
Grant Golden scored 24 points for Richmond (3-12, 1-2), Gilyard had 13 and Fore, 11.
Miami Hurricanes forward Dewan Huell had decided to return for his junior season after pulling out of the NBA draft.
The NCAA has granted Florida State forward Phil Cofer's request for another year of eligibility.
Kansas State's Barry Brown Jr. has withdrawn from the NBA draft and will return to the Wildcats for his senior season.