After Lipscomb's Malcolm Smith made a layup to draw the game to its fourth tie, 27-27, Hall converted two free throws that sparked a 16-5 run for the Bears.
Hall had eight points during the run and Smith added a 3-pointer.
Mercer (13-9, 6-3) shot 34.8 percent (8 of 23) in the first half but hit 11 of 16 after intermission en route to its third win in four games.
Deonte Alexander's 20 points led Lipscomb (8-12, 3-6), which made 9 of 31 second-half shots.
Authorities say former Michigan State basketball player Keith Appling has been charged with carrying a concealed weapon and other crimes.
Point guard Jaylen Fisher, who reopened his recruitment after coaching changes at UNLV, has committed to TCU over a long list of schools.
Forward Kennedy Meeks, who has averaged 9.4 points and 6.5 rebounds at North Carolina, has pulled out of the NBA draft and will return to the Tar Heels.