This was the third straight year Ragland has beaten Collinsville in the Northeast Regional.
The Purple Devils, who made the Final Four a year ago, will face either Sacred Heart or Spring Garden on Friday at 5:20 p.m.
Ragland was led by Levi Campbell's 14 points. Shawn Wright and Jaylen Brewster added 11 points each and Kijana Lindsay had 10 rebounds.
Collinsville biggest contributor was Jeffrey Campbell, who scored 14 points. Jalyn Martin added 11 points and a team-high seven rebounds.
Ragland (16-8) survived a Collinsville's comeback in the fourth quarter after taking a 12-point lead into the final period. The Panthers (22-10) cut the deficit to eight points in the final minutes of the game, but were never able to get closer.