McKnight made 7 of 14 field goals for Miami (2-1) and Will Sullivan added 12 points.
A jumper by Theo Johnson gave Liberty (2-2) a 41-40 lead with 10:34 left before an 8-0 run gave the Redhawks a seven-point lead with about 5 1/2 minutes to play.
The Flames pulled within three, 52-49, when Johnson made a layup with 2:20 remaining, but Miami made 11 of 16 free throws from there to seal it.
Liberty, which shot 47.8 percent in the first half and took a 27-24 lead into the break, made just 6 of 21 field goals (28.5 percent) in the final 20 minutes.
Andrew Smith scored 13 points and grabbed seven rebounds in the loss.