Lawrence trailed by 12 at the half but rallied to take a one-point lead with 5:28 left. The Scots came back to lead by as many as five points, but Claire Getzoff's layup with 18 seconds left trimmed the lead to 66-63.
Lisa Curry missed a jumper for Monmouth with five seconds remaining, and Kelly Mulcahy grabbed the rebound for the Vikings. Lawrence was unable to get a shot off before the final buzzer sounded.
Mulcahy led Lawrence (14-2, 7-2 MWC) with 16 points. Getzoff added 11 points, and Jenny Stoner had 10 points and eight steals.
Ashley Yeast powered the Scots (7-9, 4-5) with a game-high 17 points and 14 rebounds. Curry added 15 points and Melissa Gorski had 12.
Lawrence was down 48-37 with 13:04 left in the game, but the Vikings went on an 18-6 run to grab a 55-54 lead. Mulcahy scored eight points in that outburst and Getzoff added six.
The Scots responed by scoring the next six points, and Lawrence never got closer than three points the rest of the way.
Lawrence travels to Grinnell for a 2:00 p.m. game on Saturday.