UCF was hampered by some first-half turnover issues, but began the second half on a 23-6 run to take a 61-35 lead with 12:50 left to take control.
The win snapped a two-game losing streak for the Knights, who hadn't played since their Nov. 23 loss at Florida.
Saturday was the season debut for Williams, an Orlando high school-product, who missed the start of the season after having an appendectomy.
Williams was diagnosed with appendicitis just two weeks before the start of the season and spent two weeks in the hospital, dropping 20 pounds.
He was cleared for contact in practice just this past Thursday.
UCF coach Donnie Jones planned to play him no more than five minutes Saturday before he started to heat up from beyond the arc. Williams went 7 for 9 from deep, completing his scoring barrage in just 13 minutes of action.
Williams wasn't the only one hot from the 3-point line. Fellow freshman Daiquan Walker was 5 for 6 on the night, scoring 15 points.
The only sore spot UCF was at the free throw line, where the Knights went 12 for 23 for the game.
The Knights took a 38-29 advantage into halftime, but led by as many as 11 in the opening 20 minutes.
UCF pushed the tempo and pressed Florida Tech for most of the half, but it was the Knights that had trouble hanging onto the ball with 14 turnovers.
Florida Tech didn't shoot particularly well, but got 14 first-half points from Reid.
Defensively, the Panthers tried to negate the Knights' size with a zone. It confused the Knights at times, leading to nine Florida Tech steals.
The cushion that UCF did get was thanks to the 55 percent (15 for 27) in shot the half. Keith Clanton was 4 for 5 from the field and had 11 points.
UCF now must endure an 11-day layoff before it hosts Bethune-Cookman University on Dec. 12.
Florida Tech is also off for a week, returning home to host Devry Dec. 8.
Should the Lakers take Ben Simmons or Brandon Ingram if they get the No. 1 pick? And how does the rest of the top 10 shake out? Our Insiders run their latest mock draft, with L.A. on the clock.
Shaka Smart lost five seniors and his best player. But behind a trio of talented underclassmen, the Longhorns could be building something special.
High school junior Zach Brown, a 7-footer from Miami, has rescinded his commitment to UConn, sources told ESPN.