The Mighty Macs closed with a 12-5 run over the final four minutes to erase a two-point deficit and earn their second straight home win.
Sean Fordham hit a go-ahead three-pointer with 3:04 remaining in the game to put Immaculata up 59-58. Lopez converted a traditional three-point play on Immaculata's next possession to give the Mighty Macs a four-point lead.
Neumann closed within two points on a field goal by Elisha Hannibal with 56 seconds remaining, but the Knights would get no closer.
Kris Behm and Dan Lepone each added 13 for the Mighty Macs, who shot 44 percent from the field.
Mike Hitchins scored 12 points for Neumann.