Florida won its 14th consecutive game and extended a school record with its 28th straight victory at home.
Frazier came up huge in the latest one. The sophomore drained three 3-pointers in a 2-minute span in the second half, giving Florida some breathing room in a tight, back-and-forth game. Frazier, who missed all four shots from behind the arc in the first half, made 4 of 7 after the break.
"Him giving up an open 3 is like a turnover because it's probably one of the best shots we can get as a team," center Patric Young said.
Young's driving layup with 4:10 remaining gave the Gators (20-2, 9-0 Southeastern Conference) a 58-48 lead. It showed Florida's concerted effort to work the ball inside-out, something that rarely happened in the first half against Missouri's zone.
Missouri's 3-point shooting kept the Tigers (16-6, 4-5) in it for much of the game.
Missouri made 8 of 21 from behind the arc, but just 4 of 13 in the second half. The Tigers went more than 4 minutes without a point, a stretch that helped Florida build its biggest lead.
"We knew it was going to be a slugfest," Missouri coach Frank Haith said. "We were OK with that. ... Our game plan was good and we were executing. Then they got going. They got it in the paint, they got to the free throw line and got aggressive there in the second half, and that was the difference in the game."
Jabari Brown led the Tigers with 15 points while Jordan Clarkson added 14.
Scottie Wilbekin finished with a career-high 19 points for the Gators. He was 13 of 16 from the free throw line, most of them down the stretch. Young chipped in 13 points and six rebounds.
But Frazier's 3s were the key.
"He's one of a kind," Wilbekin said. "There's not too many shooters out there that's better than Frazier."
Florida coach Billy Donovan notched his 16th consecutive 20-win season. Only Syracuse's Jim Boeheim and Duke's Mike Krzyzewski have longer active streaks.
Donovan's current team has some issues -- shaky free throw shooting and few long-range threats outside Frazier -- but the addition of Walker could increase Florida's chances of making another deep run in the NCAA tournament.
A forward from Bonifay in Florida's panhandle, Walker sat out 12 games, or 40 percent of the season, because the NCAA determined he "received preferential treatment from five people, including two agents." The NCAA said Walker and people close to him accepted free cellphones and service, airfare, lodging, meals and apparel while he was a prospect.
"I was like 16 or 17," Walker said. "I really had no idea about the rules and everything."
Walker was ordered to donate the $270 received from the agents to a charity of his choice and serve 80 hours of community service.
After failing to qualify academically and spending the fall taking online classes to gain eligibility, Walker joined the team Dec. 14 and has been practicing since. His debut, though, was on hold as the NCAA wrapped up its investigation. He was cleared to play last week, setting up his much-anticipated debut.
He drew ooh's and aah's with every move during pregame warm-ups. He got a standing ovation as he entered the game with 11:28 remaining in the first half. His first few minutes on the court gave Florida fans even more to celebrate.
Walker blocked two shots and pulled down a rebound in just 3 minutes. There was some obvious confusion, especially on the defensive end, but he showed surprising poise considering all the hype, the wait, the atmosphere and the opponent.
"Just happy he can finally get on the floor and contribute a little bit," Donovan said.
Walker was even better in his second stint.
Walker had two thunderous dunks in the final 2:07 of the half, finishing alley-oops from fellow freshman and former AAU teammate Kasey Hill. The second one had the O'Connell Center rocking -- but just briefly.
Brown hit a 3-pointer at the buzzer a few seconds later, giving Missouri a 28-25 lead.
"I'm just so glad to have it behind me," Walker said. "My coaches and teammates have been behind me. ... All I want to do is play my role and do anything I can to help the team win."