CHICAGO — There was still over a minute and a half left to play, but the exclamation point had already come on Indiana’s 80-64 win over Illinois.

Yogi Ferrell stole the ball and Victor Oladipo slammed home a 360-degree dunk on the other end to give the top-seeded Hoosiers a 20-point lead.

Oladipo wasn’t sure what he was going to do with the dunk until he was in the air.

“It was just a last-second thought,” he said after the top-seeded Hoosiers defeated Illinois for just the second time in seven Big Ten Tournament meetings between the schools. “I thought about it while I was in the air, so I just kind of turned around when I was in the air.

“And no, that’s not my best (dunk).”

The victory sends Indiana (27-5) into a semifinal matchup today with Wisconsin (22-10), a 68-59 winner over Michigan on Friday. The Hoosiers have lost 11 straight to the Badgers, including a 64-59 loss in Bloomington in January.

Oladipo had just two points in the first half, but his defense helped the Hoosiers hold Illinois (22-12) to 21 points and 7-of-27 shooting from the field in the first half.

Illinois kept it close to start the second half and cut the lead to single-digits for the first time in over 20 minutes of game time when D.J. Richardson hit two free throws with 8:17 to play.

That made the score 60-52 in IU’s favor — the Hoosiers never trailed — but Oladipo made a layup and Christian Watford hit a 3-pointer, and the Illini wouldn’t get closer than 11 points the rest of the way.

“I told these guys after the game, you’re playing a team that’s been ranked No. 1 in the country more than any other team in college basketball and you shoot 27 percent and 16 percent from three and turn the ball over eight times, and you’re (only) down 14,” Illinois coach John Groce said.

“Had they not showed the resiliency and toughness that they did in the first half, we would have been down a lot more. … Offense good second half, defense good first half. When you’re playing Indiana, you’ve got to be good in both, on both offense and defense, both halves.”

The Hoosiers weren’t exactly shooting lights out themselves in the first half, making 12 of 27 from the field. But IU made 15 of 23 shots from the field in the second half and was 11-of-12 from the free throw line.

“We closed the game the last seven minutes, not only defending pretty well, but scoring very well. That’s the key,” Indiana coach Tom Crean said.

Oladipo finished with 12 points and a game-high 11 rebounds for his second straight double-double. Cody Zeller led the Hoosiers with 24 points on 9-of-11 shooting, Watford scored 15, Yogi Ferrell scored 11 and Will Sheehey added 11 points off the bench as IU improved to 16-1 this season when scoring 80 points or more.

Tracy Abrams and Brandon Paul scored 16 each to lead Illinois, while Joseph Bertrand added 10 points. The Illini now wait to see if they’ll be an NCAA Tournament team.

“We’re excited for Sunday to see what happens,” said Paul, who was just 2-of-13 from the field thanks to Oladipo’s defense. “Once we put two halves together, we’re going to be a force to be reckoned with.”

Meanwhile, the Hoosiers look for revenge against the Badgers.

“Our whole focus was getting ready to play our best basketball today and hopefully we play even better basketball tomorrow,” Crean said. “Never to look ahead and to stay totally locked into the game at hand.”