Freshman Wes Clark had been three for 23 from the field in SEC play, but he connected on two pull-up jumpers, , including a 15-foot swish off a curl in from the right wing midway through the half.
Arkansas started one for nine from the field and finished the first half 10 of 27 overall for 37 percent.
With 1:16 left, Jordan Clarkson drove into the lane, drew the defense and then found Earnest Ross at the top of the key for the go-ahead three-pointer.
Missouri hit 16 of 16 free throws in the second half.
Clarkson grows at point for Tigers
Clarkson didn’t have a tremendous night offensively. He was four of 11 from the field and missed all three second-half field-goal attempts.
But Clarkson drew postgame raves for the job he did handling Arkansas’ pressure and creating for teammates.
“He had a yeoman’s effort tonight,” Missouri coach Frank Haith said. “He grew as a point guard tonight. They pressured him all night, but he made really good decisions.”
Clarkson scored 11 points, but it was six assists and only three turnovers that proved more pivotal.
“They were trying to clog the paint on my drives, so I had to make plays for other people and find them,” Clarkson said. “They did a good job knocking down shots. Just trusting my teammates was a big step for me tonight.”