The result was an 88-71 win for the Buckeyes over Purdue on Friday night in Indianapolis.
The third-seeded Buckeyes built a 13-3 lead in the opening five minutes, but sixth-seeded Purdue rallied to tie the game at 24 on a jumper by D.J. Byrd with 7:12 to go in the first half.
The Buckeyes answered with a 7-0 run to go ahead 31-24. They capped the spurt with a three-point play by Lenzelle Smith Jr., who caught a pass from Buford while streaking to the rim and powered home a layup while being fouled. He added the free throw after the under-eight media timeout.
Byrd, who would finish with a team-high 20 points, struck again from long range on the next Purdue possession to set the deficit at four, the same margin it would be at the half after a back-and-forth final five minutes of the first.
The Buckeyes built a pair of double-digit leads in the second half, but only the second one stuck.
Leading 62-59, the Buckeyes pounced with seven minutes left as William Buford spun through the middle of the lane for a layup and a foul on Anthony Johnson. He converted the ensuing free throw to kick off a 17-2 run that put the game out of reach.
Byrd answered with a driving layup, but it was all Buckeyes for the next three minutes. Ohio State forward Deshaun Thomas put back a Sam Thompson miss, then Sullinger scored in the post and Buford produced another old-fashioned three-point play.
Buford, the team's only senior, followed with back-breaking three at the 4:54 mark, and the Buckeyes could smell a second-round matchup Saturday with No. 2 seed Michigan.
Thomas rounded out the spurt with a jumper from the baseline and a fastbreak layup and the Buckeyes had a 79-61 advantage with under four minutes to play.
Though there was a tendency to focus on offense as the Buckeyes shot 60.7 percent from the field and scored 88 points, they said defense was the key to the sequence that decided the game.
"We had five guys connected on defense," Buford said. "And when we do that, it's pretty tough to score against us. That let us get our run, let our defense lead our offense."
"Finally when we broke out on that run, I thought our communication was great because everybody was talking," Sullinger said. "And like Coach Matta always tells us, when we talk on the defense end, it always carries over to the offense end, and I thought that's what made us break away."
Sullinger had only one basket in the decisive run, but he did most of the damage the rest of the night. The Buckeyes' sophomore big man totaled 30 points and grabbed 12 rebounds, taking advantage of a size advantage inside by making 12 of 17 field goals and adding five free throws.
"Honestly, not trying to toot my own horn, but we played through me," he said. "Obviously, when we see the double, our guards understand that if they get into the open spot, they're going to have a knockdown jump shot, or if they don't double, they're going to let me go work. So I thought that was the biggest key to this game."
Thomas added 22 points on 9 for 13 shooting while Buford and Smith had 11 apiece.
Point guard Aaron Craft added 10 points, seven assists, six rebounds, two blocks and a steal while he committed only one turnover in 38 minutes.
The Buckeyes and Wolverines, who along with Michigan State tied for the regular season Big Ten championship, are set to tip off at approximately 4 p.m. on Saturday. The game will follow Michigan State taking on fourth-seeded Wisconsin.