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.
Pirates catcher Jacob Stallings, the son of University of Pittsburgh basketball coach Kevin Stallings, made his major league debut on Sunday night.
Who made the biggest impact at the NBPA Top 100 camp? We update several top prospects such as Zion Williamson.
The only thing that can sink John Calipari's star-studded ship is a leadership void, but Isaiah Briscoe seems to have that covered.