The Bulldogs (21-13) raced to a 21-2 lead in the opening minutes. Although Arkansas wiped out that entire deficit before halftime, Butler took control again early in the second.
The Bulldogs advance to play second-seeded Purdue on Sunday.
After falling behind by 19 early, Arkansas rebounded impressively with a 27-6 run, but the Razorbacks' lead was brief, and Butler was up 36-31 at halftime.
The Bulldogs quickly pushed the lead back to double digits in the second. Martin, who surpassed 2,000 points for his career during the game, made two 3-pointers in a 9-2 run that made it 49-38.
The Arkansas pregame notes noted that Gafford had 27 more dunks this season than Butler's whole team, but it was the Bulldogs who threw down the first one of this game when Tyler Wideman slammed in an offensive rebound to make it 7-2. Another Butler dunk -- this one by Baldwin -- made it 18-2, and after a 3-pointer by Martin, the Razorbacks used their second timeout of the half.
Arkansas answered with a quick 10-0 run, and although Gafford was contributing little offensively, the Razorbacks came all the way back and took a 29-27 lead on a 3-pointer by C.J. Jones.
The Razorbacks came in shooting 40 percent from 3-point range, but they went just 4 of 18 in this game and didn't have enough threats inside to make up for that.
Arkansas heads into the offseason and will have some changes on the horizon. This team had three senior starters.