Kroeger, a freshman guard, hit 13 of 18 shots from the floor, grabbed six rebounds and handed out four assists, as Lawrence remained the lone unbeaten men's team in the country. The Vikings are now 16-0 and 10-0 in the conference.
All-America forward Chris Braier turned in another double-double with 19 points and 20 rebounds. Kyle MacGillis also had a double-double for the Vikings with 26 points and 10 rebounds.
John Grotberg led Grinnell (10-6, 6-4) with 27 points.
It was a low-scoring affair for the Pioneers, who were held more than 40 points below their season average.
Lawrence led 43-39 at the half and pulled away midway through the second half.
The Vikings went on a 16-6 run to take an 88-68 lead with 7:15 left in the game. Andy Hurley capped the run with the last four points for the Vikings.
Lawrence never led by fewer than 13 points the rest of the way.
The Vikings are back on the road when they travel to Ripon on Tuesday.