Matthews made 6 of 7 3-point attempts to lead Portland to its first preseason win in three games. C.J. McCullum made five 3-pointers and scored 19 points.
Blazers All-Star forward LaMarcus Aldridge went 8 of 8 from the free throw line and scored 16 points.
Los Angeles went 19 of 39 from 3-point range, including a 6-of-7 performance from Crawford.
Portland guard Damian Lillard missed his second consecutive preseason game because of strained left foot. McCullum started in his place.