Collinsworth scored 23 points, grabbed 12 rebounds and had 10 assists. His five triples moves him past Michael Anderson (1985-86), Brian Shaw (1987-88), Jason Kidd (1993-94) and Stephane Lasme (2006-07) on the season record list with four apiece.
The NCAA career triple-double mark is six, held by Anderson (1985-88) and Shaquille O'Neal (1990-92).
BYU (18-8, 8-5 West Coast) made a 9-0 run toward the end of the first half - as LMU went over five minutes without a basket - and the Cougars led 40-30 at the break. Collinsworth had 14 points in the half.
The Cougars pulled away for good after a 9-0 spurt made it 79-59 with 3:36 left. Tyler Haws added 22 to the effort.
Marin Mornar led LMU (8-17, 4-9) with 17 points.