The victory keeps the Vikings (16-2) tied with Carroll for first place in the Midwest Conference at 9-2.
Lawrence trailed 11-0 to start the game and was down by as many as 13 points in the first half, but the Vikings battled back. Claire Getzoff's layup at the first-half buzzer cut Ripon's lead to 35-30 at the break.
The Vikings took their first lead at 44-42 on a pair of Van Groll free throws with 14:16 left in the game. Lawrence went on to lead by as many as nine points before Ripon countered.
The Red Hawks tied the game at 65-65 with 2:17 remaining. Getzoff answered for the Vikings with a 3-pointer, and after an Anne Ackerman miss, she stroked another jumper to put the Vikings up 70-65 with 1:13 left.
The Vikings then sealed the win at the foul line. The Vikings hit 6 of 7 free throws in the final 49 seconds.
Morgan Roberts and Karalyn Dehn both hit 3-pointers for Ripon to cut Lawrence's lead to74-71 with 25 seconds left. The Red Hawks had a chance to tie, but Mona Delsman misfired on a 3-pointer, and Van Groll grabbed the rebound. She then hit a pair of free throws to put the game away.
Van Groll hit 6 of 8 shots from the floor and was 11 of 13 from the foul line to lead the Vikings. Kelly Mulcahy added 18 points for Lawrence, and Getzoff finished with 14.
Dehn paced Ripon (11-7, 8-3) with 29 points and nine rebounds.